Definition from Wiktionary, the free dictionary
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
area of ground on the enemy's side of an obstacle