bridgehead

UK: /ˈbrɪdʒhɛd/ US: /ˈbrɪdʒˌhɛd/ ,(brij′hed′)

WordReference Random House Learner's Dictionary of American English © 2025

bridge•head /ˈbrɪdʒˌhɛd/   n. [countable]

1. Military a position taken by an army on the enemy side of a river to protect the crossing of friendly troops:
   established a bridgehead and began moving up troops.

WordReference Random House Unabridged Dictionary of American English © 2025

bridge•head  (brij′hed′), n. 

1. a position held or to be gained on the enemy side of a river, defile, or other obstacle, to cover the crossing of friendly troops.
2. any position gained that can be used as a foothold for further advancement;
   beachhead.
3. a defensive work covering or protecting the end of a bridge toward the enemy.

• bridge¹ + head 1805–15

Collins Concise English Dictionary © HarperCollins Publishers::

bridgehead / ˈbrɪdʒˌhɛd/ noun

1. an area of ground secured or to be taken on the enemy's side of an obstacle, esp a defended river
2. a fortified or defensive position at the end of a bridge nearest to the enemy
3. an advantageous position gained for future expansion