BRIDGEHEAD

bridgehead

(noun) a defensive post at the end of a bridge nearest to the enemy

bridgehead, foothold

(noun) an area in hostile territory that has been captured and is held awaiting further troops and supplies; “an attempt to secure a bridgehead behind enemy lines”; “the only foothold left for British troops in Europe was Gibraltar”

Source: WordNet® 3.1

Etymology

Noun

bridgehead (plural bridgeheads)

An area around the end of a bridge.

(military) A fortification around the end of a bridge.

(military) An area of ground on the enemy's side of a river or other obstacle, especially one that needs to be taken and defended in order to secure an advance.

(chemistry) Either of the two atoms in different parts of a molecule that are connected by a bridge of two or more other atoms

Source: Wiktionary

Bridge"head`, n.

Definition: A fortification commanding the extremity of a bridge nearest the enemy, to insure the preservation and usefulness of the bridge, and prevent the enemy from crossing; a tête-de-pont.

Source: Webster’s Unabridged Dictionary 1913 Edition