Gabion - A basket of a cylindrical form, filled with earth, either to carry on the approaches under cover during a siege, or in field-work. Parapets are often constructed of gabions. To construct gabions, some staves of the length of three or four feet are stuck into the ground, in the form of a circle, wattled together with osier twigs.

Gabionade - A retrenchment hastily thrown up. A parapet constructed of gabions is termed a parapet en gabionade.

Gallery - An underground passage leading to the mines. The term also is used for a communication between the interior and the exterior works of a fortified place.

Gantlet or Gauntlet - An iron glove. To throw down the gauntlet, in military acceptation, is to challenge; to take up the gauntlet is to accept the challenge.

GCM - General court martial

General Officer - An officer above the rank of colonel.

Generalissimo - The chief officer in command in the field.

Glacis - The slope of the parapet of the covered way.

Grand Division - A body of troops composed of two companies. A regiment or battalion being told off in divisions of two companies, each is said to be told off in grand divisions - Grand division firing is when a battalion fires by two companies at the same time, and is commanded by only one officer.

Grappling Irons - Irons thrown at an object for the purpose of dragging it nearer.

Grenade - A hollow ball or shell of iron or other metal, about two and a half inches diameter, which being filled with fine powder, is ignited by means of a small fuse. It derives its name from having been formerly thrown by the grenadiers of regiments.

Guard - A body of men to protect an army or a place from being surprised. The Advance or Van Guard is a party of cavalry or infantry, or of both arms, which marches before the main body, for the purpose of apprising it of any approaching danger. A Rear Guard is that part of an army or body of men which brings up the rear of a march, for the purpose of preventing the enemy from gaining ground on the flanks of the main body. The term is also applied to a corporal placed in the rear of a regiment, to keep good order in that part of the camp. Main Guard, that from which all other guards are detached. Port Guard, a guard detached from the main guard. A Grand Guard is a guard composed of three or four squadrons of cavalry, commanded by a field-officer, and posted about a mile from the camp for its better security. An Advanced or Quarter Guard, is a guard or detachment intrusted with the guard of a post. Quarter Guard, is a small guard posted in front of each battalion in camp. Picket Guard, see Picket. Guards are either ordinary or extraordinary. Ordinary, when mounted in camp or garrison towns; extraordinary, when detached to cover foragers , escorts, etc. To Relieve Guard, is to put fresh men or sentries on guard. To turn out the Guard, is to form the guard for the purpose of receiving a general or commanding officer; also, on the approach of an armed party, or on the beat of the drum, sound of trumpet, or any alarm. To turn out the Guard, is to form the guard for the purpose of receiving a general or commanding officer; also, on the approach of an armed party, or on the beat of the drum, sound or trumpet, or any alarm.

Guard-Mounting - Is the hour at which a guard is mounted.

Guerrilla (Spanish for a little war). A partisan who is not enrolled and paid by the party for whom he serves. It is now, however, used to imply any irregular warfare.

Guides - Men who give information respecting the country, and the roads intersecting it.

Guidon - A cavalry standard or banner. Not used in our army parlance.

Gun (Morning and Evening). The gun fired every morning at sunrise, and every evening at sunset, to give notice to the drums and trumpets of troops in garrison, to beat and sound the reveillé, and the retreat.

Gunnery - The science of artillery, or the art of managing cannon and military projectiles.

Gun-Shot - The reach of point-blank range of a gun.

Gymnastics - The art or method of exercising the body so as to render is supple, and capable of much fatigue. Much used in the Zouave drill, recently introduced.

Halberd or Halbert - A kind of spear formerly carried by sergeants of infantry and artillery. Old Halbert, a term once used in the army to designate, a soldier who had risen to the rank of a commissioned officer. Not now in use.

Half-Pay - Allowance made to absent or retired officers.

Halting Days - Days allowed for repose when troops are on a march, and there is no necessity for exertion or dispatch.

Hang Fire (To). Fire-arms and trains of powder are said to hand fire, when a pause takes place between the ignition of the gun-powder and the application of the fire to it.

Herisson - A hedge or chevaux-de-friese, made of one stout beam, fenced with iron spikes, and fixed on a pivot, so that it revolves on being touched.

Hollow Square - The form in which a body of infantry is drawn up to resist a cavalry charge; with the colors, drums, baggage, etc., in the center.

Home Service - Military duty by citizens of towns, etc. Regular Service, is the performance of service in the army of the United States Government. Foreign Service, is service on a foreign station, beyond the limits of this country and its jurisdiction.

Honors of War - Terms granted to a capitulating enemy on evacuating a fortress.

Horn-Work - A kind of crown-work in advance of a fortress.

Hors-de-Combat (Put or Placed). Is to be killed, wounded, or disabled so as not to be capable of defense or attack.

Howitzer - A piece of ordnance for discharging shells at low angles, and shot in ricochet.

Hurdles - Oblong constructions of osier and willow twigs interwoven close together upon stakes for rendering batteries firm, or to consolidate a passage over muddy ditches, or to cover traverses and lodgments for the defense of workmen in trenches.

Impress Money - Money paid to men who have been compelled to serve. Not often used in our service.

Infantry - Foot-soldiers. The term having been applied to a body of men raised by an Infante of Spain, for the purpose of rescuing his father from the Moors; as a memorial of the deed the term was applied to foot-soldiers in general.

Inquiry (Board of). The meeting of a certain number of officers, for the purpose of ascertaining facts which may become matter of investigation by a court-martial.

Insconced - When a part of an army has fortified itself with a sconce, or small work, in order to defend a pass, etc., it is said to be insconced.

Intrenchment - A work which fortifies a post against attack. The term usually denotes a ditch or trench with a parapet. Intrenchments are sometimes made of fascines, with earth thrown over them, or of gabions, hogsheads, or bags filled with earth, as a protection from the enemy’s fire.

Invalided (To be). Is to be discharged from the service in consequence of wounds, ill-health, or long service.

Invest - Investment. The investment of a fortress is the seizure of all the avenues leading to it, preparatory to its blockage or siege.