Garrison \Gar"ri*son\, n. [OE. garnisoun, F. garnison garrison, in OF. & OE. also, provision, munitions, from garnir to garnish. See {Garnish}.] (Mil.) (a) A body of troops stationed in a fort or fortified town. (b) A fortified place, in which troops are quartered for its security. {In garrison}, in the condition of a garrison; doing duty in a fort or as one of a garrison.