Answer: bridgehead

AnswerCrossword Clue
BRIDGEHEADMilitary foothold
BRIDGEHEADFortified place of a sort.
BRIDGEHEADPart of a combat zone
bridgeheadA strong position secured by an army inside enemy territory from which to advance or attack
bridgeheada fortification protecting the end of a bridge nearest an enemy