bridge·head /-ˌhɛd/
  橋頭堡
  Bridge·head n. 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.
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  bridgehead
       n 1: 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" [syn: foothold]
       2: a defensive post at the end of a bridge nearest to the enemy