Bridgehead

n.

1.

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.

Noun	1.	bridgehead - 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" Synonyms: foothold
	2.	bridgehead - a defensive post at the end of a bridge nearest to the enemy

acropolis, advance guard, airhead, avant-garde, bastion, battle line, beachhead, blockhouse, bunker, castle, citadel, donjon, farthest outpost, fasthold, fastness, first line, forefront, fort, fortress, front, front line, front rank, front-runner, garrison, garrison house, hold, keep, line, martello, martello tower, mote, motte, outguard, outpost, peel, peel tower, pillbox, pioneer, point, post, precursor, railhead, rath, safehold, scout, spearhead, strong point, stronghold, tower, tower of strength, van, vanguard, ward