Definition of: bunker

(bung′kər) noun
1. A large bin, as for coal on a ship.
2. A box or chest that serves also for a seat.
3. In golf, a sandy hollow or a mound of earth serving as an obstacle on a course.
4. Mil. a A steel and concrete fortification, usually underground. b A bulwark of earth erected to protect a gun emplacement.
—v.i. To fill the coal bunkers of a ship.
—v.t. In golf, to drive (a ball) into a bunker. [Cf. OSw. bunke hold of a ship and BANK³ (def. 2)]