%AC-47 : A two engine, DC-3 type aircraft used to provide fire support to soldiers on the ground.

ACAV. Armored cavalry assault vehicle. A modified %M-113 with one M-2 and two M-60 machine guns.

%AK-47 : Russian designed 7.62mm assault rifle. Very rugged and dependable.

Ambush Patrol. A small group of soldiers, usually five or fewer, set up at night, outside the main Laager or NDP, to intercept enemy soldiers on the move in the immediate vicinity.

Army Brat. A term used, with pride, by the children of army personnel to describe themselves.

BAR. Browning automatic rifle. A .30 caliber automatic rifle with a 20-round magazine used in WWII and Korea. Replaced in the US inventory by the M-60 machine gun.

BOQ. Bachelor Officer Quarters. On-base housing for unmarried officers. Usually consisting of a bedroom, bathroom, and shared kitchen facilities.

Ball Ammunition. Regular ammunition, as distinguished from Tracer Ammunition

%Battalion : US Army formation commanded by a lieutenant colonel containing four batteries or companies.

Battery. A US artillery unit, commanded by a captain containing about 100 soldiers and six cannon. Equivalent to a company.

Bazooka. A shoulder fired anti-tank weapon system employing a rocket propelled shaped-charge projectile

Body Count. The number of enemy soldiers killed. A key, but often inaccurate metric used during the Vietnam War to measure success.

Brigade. US Army formation commanded by a colonel containing two or more battalions.

Bush. Slang for the jungle.

Butt Pack. A canvas pack worn on a soldier's web gear harness, in the lumbar region, to carry essential equipment.

C-7. A twin-engine army medium transport aircraft called the Caribou.

CH-47. Large multi-purpose helicopter, known as the Chinook.

%C-123 : The Provider. A two-engine air force transport aircraft used for paratroop training and combat resupply.

%C-130 : Four engine transport aircraft capable of landing on dirt airfields.

CO. Commanding Officer. Usually referring to a company commander.

Charlie. Slang for Viet Cong, pronounced phonetically as "Victor Charlie."

CP. Command Post. Location of commander and his key personnel where the command and control function is accomplished.

Colt .45. Standard issue .45 caliber semi-automatic pistol.

Command Group. The commander, his key staff and associated RTOS required to accomplish the command and control function.

CIDG. Civilian Irregular Defense Group. Groups of local Vietnamese recruited by the US Special Forces as mercenaries, who usually lived with their families in the Special Forces camps when not on patrol or interdiction missions along the border areas.

Claymore. A small, shaped charge, anti-personnel mine, firing ball bearing size projectiles.

Company. US Army formation commanded by a captain with about 185 soldiers organized as four platoons and a headquarters element.

Donut Dolly. Slang for a Red Cross girl (serving coffee and donuts).

F-4. US fighter-bomber, commonly called the Phantom, used to support soldiers on the ground.

F-105. US fighter-bomber, commonly called the Thunder Chief, used to support soldiers on the ground.

FDC/FDO/FO. Fire Direction Center. A place where soldiers working under the FDO, Fire Direction Officer, compute the settings to be transmitted to the guns to hit the target radioed in by the FO, Forward Observer.

Fire Team. A sub-element of a squad containing four to five soldiers.

First Sergeant. The senior NCO in a company or battery. Revered for their toughness, wisdom, experience, maturity, and judgment. Roughly equivalent to the fabled Roman Centurion.

FM. Field Manual. Official, authoritative US Army publications containing approved doctrine, tactics, techniques, and procedures for all combat and combat support activities.

Four Deuce. 4.2-inch mortar.

Fourragere. A cloth and metal shoulder loop representing a military award, distinction, or membership in a unit.

Friendly Fire. Artillery, air strikes, and ground fire from our own forces which inflict unintentional friendly casualties.

GP Small/ Medium Tent. US Army general purpose tent that can nominally sleep 4 and 10 soldiers, respectively.

HAWK. Homing All the Way Killer. A US radar and missile medium altitude anti-aircraft weapon system.

Happy Hour. Time set aside in military clubs for reduced price drinks and other special attraction to encourage attendance and promote comradeship.

Headspace and Timing. Pre-firing adjustments to the M-2 machine gun bolt and firing pin assemblies to ensure proper functioning of the gun in automatic fire.

Honest John. A US surface-to-surface missile system.

%Howitzer : relatively high angle of fire artillery piece. Can be fired from behind a hill mass between it and the target.

Huey. Standard US UH-1 helicopter used in Vietnam to transport troops, supplies, and serve as fire support platform firing rockets.

Hump. Slang for trudging through the jungle (the Bush).

KP. Kitchen Police. A term describing various clean up and serving duties in support of the cooks, assigned to (non-cook) soldiers on a roster basis to ensure fairness.

Laager.  A type night defensive position (NDP) for a battalion or larger unit in the field, from which to be resupplied by helicopter in preparation for continued operations at daybreak.

Leg. A term of derision for non-paratroopers. Referring to soldiers who have to walk, using their legs, to get to the fight, as opposed to paratroopers who jump into the fight.

Lensatic Compass. Standard army compass used for navigation and adjustment of indirect fires.

LZ. Landing zone. A natural or man-made clearing to accommodate helicopters.

M-1 Carbine. Standard light .30 caliber rifle/carbine used in WWII and Korea. Capable of automatic fire. Used a smaller, less lethal, round than the M-1 rifle. Had a 20-30 round magazine. Replaced by the M-16 during the Vietnam War.

M-1 Rifle. Standard US Army .30 caliber semi-automatic rifle used in WWII and Korea. Had an eight round clip. Replaced by the M-16 during the Vietnam War.

M-2 machine gun. Heavy US Army caliber .50 machine gun.

M-16. Standard 5.56 mm rifle issued to soldiers in Vietnam. Capable of automatic fire. Had a 20-round magazine.

M-17 Protective Mask. Standard US Army "gas mask." Worn on left side, in a canvas case.

M-48. Standard medium US tank used in Vietnam.

M-60. Light, 7.62mm machine gun.

M-113. Standard US Army tracked, tank-like armored personnel carrier (APC). Could carry upwards of ten soldiers (a squad).

M-1911 caliber .45 Colt pistol. Standard side arm from WWI onward. Semi-automatic with a seven-round magazine.

Mortar. A relatively simple high angle of fire weapon system capable of firing from behind a hill mass or other barrier between it and the target.

NCO. Non-commissioned officer. A soldier in the rank of Corporal to Sergeant Major. Most commonly used as a generic term for any grade of sergeant.

Napalm. Jellied gasoline bomb fill. Highly combustible upon detonation.

Nike Hercules. A US radar and missile high altitude air defense weapon system.

NDP. Night Defensive Position. A temporary position for company size units or smaller, from which operations will be resumed at daybreak.

OCS. Officer Candidate School. A training process to produce officers from the enlisted ranks.

OH-13. A light, two-man observation and command and control helicopter.

Officers Field Ration Mess. A dining facility for officers offering standard army-issue food, at a fixed rate.

Out. Radio brevity code word meaning, "I have nothing further to transmit."

PRC-25. Portable Radio Communications. The standard back-pack FM field radio used in Vietnam.

PX. The Post Exchange. An on-base army facility offering clothing, toiletries, jewelry, furniture, garden, and other department store-like items.

Platoon. US Army formation containing 44 soldiers organized as four squads and a headquarters element.

Point Man / Slack Man. The Point Man is the first in line in a tactical formation, responsible for maintaining the compass direction and pace count (distance travelled). He must be able to "read" the environment for signs of the enemy. The soldier to his immediate rear is the Slack Man. He covers the Point Man, maintains a pace count, and provides over-watch security. These are the two most important and dangerous jobs for an infantry unit moving tactically.

RC-292. A man-portable FM radio antenna mounted on a sectioned mast.

ROTC Summer Camp. A six-week basic training camp for ROTC cadets between their junior and senior years.

RPG. A rocket propelled grenade with a shaped charge warhead, used by the Vietcong to attack US vehicles, bunkers, and even hovering helicopters.

RTO. Radio-telephone operator. The soldier who carries the PRC-25 field radio, commonly called the "Prick 25."

R&R. Rest and recuperation leave. A one-week leave granted to each soldier to such locations as Australia, Hong Kong, Thailand, The Philippines, and Hawaii.

Recoilless Rifle. A weapon system firing a relatively low velocity projectile with a shaped charge warhead. Part of the propellant charge is allowed to exhaust at the breech end, producing a rearward momentum which counterbalances the forward momentum of the projectile. The net effect of this momentum balance is no recoil.

Registration. The process of adjusting artillery firing tables for local metrological conditions and variations in cannon/projectile velocity in order to produce the most accurate fires possible.

Roger. Brevity code word used on the radio to mean "I have received your message and understand."

SKS Carbine. A Russian-designed forerunner of the AK-47, sub-sequently manufactured by Communist China.

S-2. Intelligence Officer on a battalion or brigade staff. In combat, primarily responsible for collecting and disseminating information on the enemy.

S-3/S-3 Air. Operations Officer on a battalion or brigade staff. In combat, primarily responsible for preparing plans and managing their execution. The S-3 Air is one of his subordinates responsible for planning and managing the execution of air support operations. On division staffs, or in separate formations commanded by a general officer, these staff officers are designated G-3/G-3 Air.

Shaped Charge. A warhead formed around an inverted, copper conical liner. Upon detonation, the conical charge blows forward, forming a hot jet of gas and molten copper which can penetrate armored vehicles.

Snipe Hunt. A fool's errand; a prank. Named for the Snipe, a shore bird that is difficult to hunt/catch. The term, sniper, derives from one skilled enough to shoot this difficult quarry.

Spoon. The handle of a hand grenade.

Squad. US Army military formation containing 10 soldiers.

Stick. A row of parachutists on one side of the airplane.

Terry and the Pirates. An American action comic/newspaper comic strip series set in China with a wartime theme. Popular from the mid---1930s to the early 1950s.

Thompson-sub-machine gun. The .45 caliber "Tommy Gun."

Topographic Map. A map representing a depiction of the terrain as seen from above, indicating elevation and shape.

Tracer. A rifle or machine gun round with an incendiary charge in its base that produces a red glowing trail to mark the projectiles trajectory as seen by the person firing it.

VRC-47. Vehicle Radio Communications. A configuration of the standard VRC-46 vehicular mounted FM radio used in Vietnam. The VRC-46 had a single transmitter and receiver. The VRC-47 had two receivers, so that two frequencies could be monitored simultaneously.

WP. Spoken as "Willie Peter." White phosphorus. A shell or hand grenade filling that produces thick white smoke when exposed to air upon detonation.

WASP. White Anglo-Saxon Protestant.

Web Gear. Term for canvas harness and belt system used by soldiers to carry canteens, packs, holsters, first aid kits, etc.

XO. Executive Officer. Usually the second in command in a company, battalion, or brigade. Usually one rank junior to the commander.