Many terms are used across the site which are specific to the war, the time period, or the military. Additionally, every time period and every war develops its own slang. Both  of these sets of terms will be defined here for clarification.

Sources include The Sixties Project, The Vietnam War Dictionary, and various memoirs and books that included lists of terms.

Please use the Contact form if you notice any errors or believe there are terms that should be added.

AATTVSee Australian Army Training Team - Vietnam

Agent Orange: A chemical defoliant, largely manufactured by Monsanto Corporation and Dow Chemical, used in Vietnam for Operation Ranch Hand.

Annam: (Vietnamese: Trung Kỳ) One of three Vietnamese regions part of French Indochina, encompassing the areas between the southern Cochinchina and the northern Tonkin. Previous to France assuming control of the region, the term "Annam" referred to Vietnam as a whole in Europe and North America.

APCSee Armored Personnel Carrier

Armored Personnel Carrier: Armored vehicle designed to transport troops and equipment in combat zones. In the Vietnam War, this largely meant the M-113 Armored Personnel Carrier which also had several variants. US Marines also used LVTP-5s which were amphibious armored personnel carriers.

Army of the Republic of Vietnam: The ground component of the Republic of Vietnam’s Military Forces. It was in existence from 1955 until the fall of Saigon in 1975.

ARVNSee Army of the Republic of Vietnam

Brown-water navy: Naval based units used in rivers and along coastlines. The vessels are not fit for open sea operations. The US Navy and RVN Navy both conducted extensive brown-water naval operations. The US Navy used mostly PBRs and PCFs. The Mobile Riverine Force was also considered a part of brown-water naval operations.

Cao Đài: Popular name for the religious sect Đại Đạo Tam Kỳ Phổ Độ. The faith was influenced by Buddhism, Christianity, Confucianism, and Vietnamese animism. It attracted many Vietnamese nationalists and became a powerful force in the Mekong Delta region until they yielded to the RVN government under President Ngô Đình Diệm in 1955. They were integrated into RVN government and military positions and held no communists within their ranks.

CAPSee Combined Action Program

Central Intelligence Agency: US federal civilian foreign intelligence service. Played extensive roles in Southeast Asia from the 1950s through the 1970s.

Central Office for South Vietnam: (Vietnamese: Văn phòng Trung ương Cục miền Nam) North Vietnamese political and military headquarters in South Vietnam.


Chiêu Hồi Program: A program developed to encourage Việt Cộng and communist supporters to defect. It involved large amounts of pro-South Vietnam propaganda, and leaflets dropped written in Vietnamese encouraging defection. These leaflets were meant to act as safe conduct passes, and if someone came to troops bearing one, they were to be welcomed and guaranteed safety. Chiêu Hồi is loosely translated to “open arms”.

CIA: See Central Intelligence Agency

CIDGSee Civilian Irregular Defense Group program

Civilian Irregular Defense Group Program: Program developed by the US Central Intelligence Agency (CIA) in 1961 to train minority tribes in Vietnam to defend themselves and resist Việt Cộng control. There was no resettlement aspect to this program. Control of the program shifted from the CIA to the US Special Forces in 1963. This led to a stronger military focus and they were sometimes hired for brief periods of time to assist in operations. The Montagnards, Khmers, Nùngs, Cao Đài, and Hòa Hảo peoples were part of this program.

Cochinchina: (Vietnamese: Nam Kỳ) One of three Vietnamese regions part of French Indochina, encompassing the six southernmost provinces of Vietnam. The name originated with Portuguese explorers in the sixteenth century and remained until 1949. The other regions of Vietnam under French control were Annam and Tonkin.

Cold War: A period of time, following WWII and extending until 1991, defined by tension between the United States of America (and allies including NATO) and the Soviet Union (along with other Eastern Bloc nations).

Combined Action Program: Developed in 1965 by the US Marine Corps, the program paired USMC units with South Vietnamese Regional Forces companies in I Corps. This was in answer to the security mission that was new to the USMC and it was hoped that the CAP program would help pacification efforts in I Corps.

Corps Tactical Zones: The Republic of Vietnam (RVN) was divided into four tactical zones in 1954 for government administration purposes as well as military purposes. The United States structured in country military command around these zones. They were numbered I, II, III, IV. See I Corps, II Corps, III Corps, and IV Corps

COSVNSee Central Office for South Vietnam

Demilitarized Zone: Ran along the 17th parallel, dividing Vietnam into North and South.

Democratic Republic of Vietnam: The official state of the area commonly known as North Vietnam between 1954 and 1975. Separated from the Republic of Vietnam by the demilitarized zone. The capital was Hà Nội (Hanoi).

DEROS: Date Eligible to Return from Overseas. A very important date for American military personnel in Vietnam, for they knew exactly how long they would be in country.

Điện Biên Phủ: French military outpost built in a valley in the Red River Delta. French paratroopers were dropped in by plane to build the outpost as all ground routes to the area were controlled by Việt Minh forces. Supplies could only reach the outpost by plane.

Điện Biên Phủ, Battle of: November 1953-May 1954 Việt Minh forces, under the command of General Võ Nguyên Giáp, carried Chinese supplied artillery pieces on their backs to reassemble on the hills surrounding Điện Biên Phủ. Air drops of supplies to the besieged French troops were captured by the Việt Minh. Daily bombardments and attacks led to the eventual French surrender on May 7, 1954. The French suffered 2,293 KIA and 5,134 WIA. Survivors were marched to Việt Minh prison camps. The battle was the final straw for the French, leading to their complete withdrawal from Indochina and to the Geneva Accords later that year.

Dink: Derogatory slur for an Asian person, used widely by American troops during the Vietnam War. 

DMZSee Demilitarized Zone.

DRVSee Democratic Republic of Vietnam

Dustoff: Medical evacuation (medevac) missions using helicopters.

Eastern Bloc: The group of communist states of Central and Eastern Europe under the political and military dominance of the Soviet Union that existed during the Cold War.

EODSee Explosive Ordnance Disposal

Explosive Ordnance Disposal: Explosive engineering profession specializing in the removal of explosive threats like bombs.

FACSee Forward Air Controller 

Fire Support Base: Artillery encampment used to support ground operations.

First Indochina War

Flak jacket/flak vest: Fiberglass-filled vest to protect against shrapnel.

FNGSee Fucking New Guy

FOSee Forward Observer

Forward Air Controller: The controller usually flew a low level spotter plane, such as the Cessna O-1 Bird Dog, to identify enemy positions and relay or mark the coordinates for air strikes of various types. They were also able to perform the same function on the ground. 

Forward Observer: Military Occupational Specialty. Those with this MOS accompany infantry units in order to call in precise artillery strikes in support of their infantry units. 

Freedom Bird: Nickname for the airplane that took troops home from Vietnam.

French IndochinaSee Indochina

FSBSee Fire Support Base

Fucking New Guy: American military members who were newly arrived in Vietnam.

Geneva Accords: Where the area of Indochina (former colony of France) was recognized as sovereign. Also stated that there would be no more hostilities and that no foreign troops would become involved in the matter. Vietnam was divided into northern and southern zones, the north governed by the Việt Minh and the south governed by the State of Vietnam (later the Republic of Vietnam). The United States did not sign this agreement, though it did acknowledge it.

Geneva Conference: (April 26 – July 20, 1954) Where in Geneva, Switzerland, the United States, the Soviet Union, the United Kingdom, France, and China (along with several other countries occasionally involved) attempted to unify Vietnam. It resulted in the Geneva Accords.

Gook: Derogatory slur for an Asian person, used widely by American troops during the Vietnam War.

Green Berets: US Army Special Forces

Grunt: Slang for infantryman.

Gulf of Tonkin Incident: A series of events in the Gulf of Tonkin including the reported attack on the USS Maddox by three North Vietnamese torpedo boats on 2 Aug 1964. Warning shots were fired by the Maddox, who was patrolling along the coast of Vietnam as part of Operation DeSoto. Torpedoes were fired at the American destroyer but they were evaded. One of the torpedo boats was damaged when the Maddox fired again, and Vought F-8E Crusaders coming to assist managed to sink the already damaged vessel.
     On 4 Aug 1964, late in the day during poor weather conditions, the USS Maddox and the USS C. Turner Joy identified various radar and sonar signals as North Vietnamese torpedo boats. Confusion reigned as the Maddox and C. Turner Joy tried to determine whether an attack was taking place.
     On 5 Aug 1964, retaliatory air strikes were ordered by President Lyndon Johnson against four torpedo boat bases. Twenty-five boats were reported destroyed and support facilities were damaged. Two American aircraft were shot down, resulting in the first American POW.

Gulf of Tonkin Resolution: Passed 7 Aug 1964 by the United States Congress. The resolution that passed was a revised draft of earlier resolutions that President Johnson had ordered written in preparation for escalated military involvement. The incidents in the Gulf of Tonkin in early August prompted another rewrite and presentation to Congress. It was passed almost unanimously with only two senators dissenting.
    The resolution allowed the president to use any measures he felt necessary “to repel any armed attack against the forces of the United States and to prevent further aggression.” Also to protect and assist any nation in the Southeast Asia Collective Defense Treaty, and the resolution would expire when the president decided it was safe to do so. For these reasons it is often referred to as a “blank check” resolution. It was repealed in 1970.
    The text of the resolution can be read here.

Gunship: Helicopter outfitted with armaments including miniguns, rocket tubes, and machine guns. Most frequently Bell AH-1 Cobras and modified Bell UH-1 Iroquois.

H&ISee Harassment and Interdiction

Hamlet: Small village

Hanoi HiltonSee Hỏa Lò Prison

Harassment and Interdiction: Firing artillery at known enemy trails and camps at random times to unbalance the enemy.

Highway 1: The main north-south highway of Vietnam that was highly contested between opposing forces during both the First Indochina War and the Vietnam War. Due to the costly and seemingly futile efforts to keep the road clear, the French referred to it as la rue sans jolie, “the street without joy”.

Hoa Hoa: Major Buddhist sect in the Mekong Delta founded in 1940. Anti-communist and anti-French/colonial, they became very powerful in the region politically and militarily. The Viet Minh sought to subdue them but failed, even after assassinating their leader. They skirmished against Cao Dai members as well as President Ngô Đình Diệm, however they were brought under RVN authority in mid-1950s.

Hmong: (Also Mong) Asian ethnic group in China and Southeast Asia. Thousands of Hmong fought alongside the French and Americans during both the First Indochina War and the Vietnam War. They also participated in the Laotian Civil War against the Communist Pathet Lao, with help from the American CIA. They were persecuted due to the roles that they played aiding anti-communist forces.

Hòa Hảo: A quasi-Buddhist religion founded in 1939 by Huỳnh Phú Sổ. Closely linked with Vietnamese nationalism.

Hỏa Lò Prison: One of several prisons in the Hanoi area that housed American POWs. It was built by the French in 1886 and previously was used as a prison for high-ranking Vietnamese officials.

Ho Chi Minh Trail: System of roads and trails reaching from North Vietnam through Laos and Cambodia into South Vietnam. It was used by the DRV to transport supplies and troops south and boasted complete support facilities along the way, mostly underground. The United States built a large air campaign designed to interrupt the flow of supplies, but it was unsuccessful.

Huey: Nickname for the Bell UH-1 Iroquois helicopter.

In Country: Slang used by the military for serving in Vietnam.

Indochina: Name for the region of southeast Asia that was once a French Colony (then French Indochina). It was comprised of the following countries: Cambodia, Laos, Vietnam. The term Indochina is seldom used now.

KIASee Killed in Action

Killed in Action: Casualty designation for service members who are killed by enemy forces.

Kit Carson Scout: A recruited Việt Cộng defector who would provide intelligence and work in the field with American troops.

Landing Ship - Tank: Ships designed to carry tanks, vehicles, cargo, and troops directly onto shore without docks or piers.

Landing Zone: Area for helicopters to land either for troops insertion, troop pick up/evacuation, or supply drop off.

Listening Post: Two or three man post established outside the perimeter at night that acted as an early warning about approaching or passing enemy troops.

Loach: Nickname for Hughes OH-6 Cayuse, a light observation helicopter

LPSee Listening Post

LRRP: Pronounced “lurp”. See Long Range Reconnaissance Patrol.

LSTSee Landing Ship - Tank

LZSee Landing Zone

MAAGSee Military Assistance Advisory Group

MACVSee Military Assistance Command, Vietnam

MACV-SOGSee Military Assistance Command, Vietnam – Studies and Observations Group

MAFSee Marine Amphibious Force

Marine Amphibious Force: Largest type of a Marine air-ground task force, the largest building block of  US Marine Corps combat power.

MEDCAPSee Medical Civil Assistance Program

MedevacSee Dustoff

Medical Civil Assistance Program: A type of civic action program to render medical aid to local populations. During the Vietnam War this would include either inviting civilians to aid posts to treat them, or bringing doctors and medics into the field to help within villages.

Mekong Delta: (Vietnamese: Đồng bằng Sông Cửu Long) Region of southwestern Vietnam where the Mekong River approaches and empties into the sea. Encompasses over 15,600 square miles.

Mekong River: (Vietnamese: Sông Mê Kông) Twelfth longer river in the world at 2,703 miles. The river runs from the Tibetan plateau through China, Myanmar, Laos, Cambodia, and Vietnam. It is a major trade route. The delta area defines a large portion of Vietnam's southwestern region where the river empties into the sea.

MIASee Missing in Action

Military Assistance Advisory Group: Organization of military advisors sent to Vietnam to help French forces and later to train RVN government forces. Precursor to Military Assistance Command, Vietnam (MACV). Operated from October 1950 to June 1964. Military Assistance Advisory Groups also operated in Thailand, Laos, Cambodia, and Taiwan.

Military Assistance Command, Vietnam: Joint-service command created 8 February 1962, absorbing MAAG within two years and commanding US forces and advisory efforts in Vietnam. MACV was dismantled in March 1973.

Military Assistance Command, Vietnam – Studies and Observations Group: Multi-service special operations force that conducted covert missions with unconventional warfare methods. Operated between 1964-1972.

Military Occupational Specialty: Specific jobs and their corresponding codes within the United States military.

Missing in Action: Casualty designation for service members who are reported missing while on active duty.

Mobile Riverine Force: Joint US Navy and US Army force that comprised the bulk of the brown-water navy. Consisted of Navy boats carrying Army infantry units. Carried out transportation of personnel and cargo, as well as combat missions. 

Montagnard: (Vietnamese: người Thượng) Indigenous peoples of the Vietnamese Central Highlands. The name originates with the French, meaning "people of the mountain," and is a holdover from the colonial period.

MOS: See Military Occupational Specialty

National Liberation Front: Armed communist political organization in South Vietnam established in 1960. Received much aid and training from North Vietnam and primarily focused on guerrilla tactics as well as pressuring local populations.

NATOSee North Atlantic Treaty Organization

NATO Phonetic AlphabetSee Wikipedia entry

NDPSee Night Defensive Position

Night Defensive Position: Established perimeter around a unit to maintain awareness during the night while members of the unit rest.

NLFSee National Liberation Front

North Atlantic Treaty Organization: Intergovernmental military alliance between 30 North American and European countries. Collective defense is a main objective of the organization.

North VietnamSee Democratic Republic of Vietnam

North Vietnamese Army: Trained regular army of North Vietnam. Also the People’s Army of Vietnam (PAVN) or Vietnam People’s Army (VPA).

Nùng: A central Tai ethnic group living primarily in northeastern Vietnam and southwestern Guangxi. During the First Indochina War, the Nùng sided with the Việt Minh. During the Vietnam War, the Nùng fought alongside the North Vietnamese Army mostly. 

NVASee North Vietnamese Army

Office of Strategic Services: World War II era intelligence agency, established 13 June 1942, dissolved 20 September 1945. Predecessor to the Central Intelligence Agency.

OSS: See Office of Strategic Services

Paris Peace Accords of 1973: Those documents establishing a cessation of direct American military involvement and a temporary cease fire between North and South Vietnam.

Patrol Boat - River: US Navy designation for a small rigid-hulled boat, specifically used in the Vietnam War from March 1966 through 1971. Used most widely in the Mekong Delta. The main mission carried out by PBR crews was the disruption of enemy weapons shipments. This mission involved searching civilian vessels, frequent firefights with enemy soldiers in boats or on shore, and transporting Navy SEAL teams and cargo.

Patrol Craft - Fast: Also known as swift boats. Aluminum, 50 ft long shallow-draft vessels, used to patrol coastal areas and interior waterways. The main missions carried out by PCF crews was to interrupt the transport of enemy weapons, transporting Vietnamese forces, and transporting Navy SEAL teams.

PBRSee Patrol Boat - River

PCFSee Patrol Craft - Fast

Phoenix Program: Designed and operated by the US Central Intelligence Agency (CIA), the program utilized special operations soldiers of the United States, Australia, and South Vietnam to “neutralize” civilian targets working for the Việt Cộng. The program ran between 1965-1972.

Post-Traumatic Stress Disorder: A mental disorder that can develop after a person is exposed to a traumatic event, including but not limited to warfare. Symptoms may include disturbing thoughts, feelings, or dreams related to the events, mental or physical distress to trauma-related cues, attempts to avoid trauma-related cues, alterations in how a person thinks and feels, and an increase in the fight-or-flight response. 

    The Diagnostic and Statistical Manual of Mental Disorders (DSM) III was the first to carry a description of "posttraumatic stress disorder." The addition of the disorder to the DSM III was heavily influenced by the conditions of Vietnam veterans. Prior to the Vietnam War, PTSD symptoms have been noted in soldiers and veterans of other wars. In the US these symptoms earned a variety of names including soldier's heart, shell shock, and battle fatigue.

POWSee Prisoner of War

Prisoner of War: A person held in the custody of enemy forces during or after a conflict.

Psychological Operations: Operations intended to convey selected information and indicators to people  in order to influence their emotions, motives, and objective reasoning. The ultimate goal is to influence the behavior of governments, organizations, groups, and individuals.

PsyopsSee Psychological Operations

PTSDSee Post-Traumatic Stress Disorder

Purple Heart: United States military decoration awarded to service members wounded or killed during hostile conflict. 

Radio Telephone Operator:

Republic of Korea: The state known as South Korea established in 1948. Ally to the United States during the Vietnam War.

Republic of Vietnam: The official state which governed southern Vietnam. It became more well known as South Vietnam after the Geneva Conference in 1954 created the DMZ, separating the country of Vietnam in two. The capital was Saigon.

ROKSee Republic of Korea

RTO: See Radio Telephone Operator

Rung Sat Special Zone: (Vietnamese: Đặc khu Rừng Sác) Name given to a large area of the Sác Forest (now the Cần Giờ Mangrove Forest), a tidal mangrove swamp encompassing about 485 square miles. Designated as a military rergion in 1962 in order to better organize defenses of the Lòng Tàu River, the main shipping channel between Saigon and Vũng Tàu.

RVNSee Republic of Vietnam

SEATOSee Southeast Asia Treaty Organization

Slick: Slang for an assault helicopter used to carry troops to and from the field. Most commonly this was a Bell UH-1 Iroquois, aka Huey.

Southeast Asia Treaty Organization: Created in 1954 as part of a regional defense scheme for the South Pacific through the Manila Pact. Members included the United States, Great Britain, the Philippines, France, Australia, New Zealand, Pakistan, and Thailand. The organization dissolved in 1977.

Strategic Hamlet Program: An initiative developed by the United States and South Vietnam to relocate civilians in attempts to decrease communist insurgency. The program was short lived, operating between 1961-1963.

“Street Without Joy”See Highway 1

Tactical Area of Responsibility: A designated area of land where responsibility for security and military operations is assigned to a commander. This is used to control assigned forces, evaluating progress, and coordinating support.

TAOR: See Tactical Area of Responsibility

Tet Offensive: A large military campaign launched by North Vietnam and the Việt Cộng to take place during the Tet Lunar New Year’s cease fire of 1968. Communist forces attacked cities and towns across I and II Corps Tactical Zones beginning during the night of January 30, the first day of the holiday. Major battles were fought in Saigon, Hue, and Khe Sanh.

Tiger Scout: Name given to Kit Carson Scouts assigned to the US Army 9th Infantry Division. See Kit Carson Scout

Tonkin: (Vietnamese: Bắc Kỳ) One of three Vietnamese regions part of French Indochina, encompassing the northernmost provinces of Vietnam.

VC: Việt Cộng, or Victor Charlie

Việt Cộng: Military arm of the National Liberation Front (NLF). Political and military organization operating out of RVN during the Vietnam War. There were various levels of involvement, ranging from regular fighting troops covering large areas to residents of towns and villages planting booby traps.

Việt Minh: A communist national independence organization. Originally established to fight for independence for Vietnam from France, they also opposed the Japanese during World War II. Following the Japanese surrender they continued to resist French rule.

Vietnamization: President Richard Nixon’s program of returning the majority of fighting responsibilities to the RVN armed forces.

WIASee Wounded in Action

Wounded in Action: Casualty designation for service members injured in a combat zone.v










© 2020 by Joseph Malek. Proudly created with

  • Grey Twitter Icon
  • Grey Facebook Icon
  • Grey Tumblr Icon
  • Grey Amazon Icon