(1):

(n.) A body of troops stationed in a fort or fortified town.

(2):

(n.) A fortified place, in which troops are quartered for its security.

(3):

(v. t.) To secure or defend by fortresses manned with troops; as, to garrison a conquered territory.

(4):

(v. t.) To place troops in, as a fortification, for its defense; to furnish with soldiers; as, to garrison a fort or town.