n. A body of troops stationed in a fort or fortified town to defend or guard it, or to keep the inhabitants in subjection.n. A fort, castle, or fortified town furnished with troops to defend it.To place troops in, as a fortress, for defense; furnish with soldiers: as, to garrison a fort or town.To secure or defend by fortresses manned with troops: as, to garrison a conquered territory.To put upon garrison duty.