[countable + singular or plural verb] a group of soldiers living in a town or fort to defend it; the buildings these soldiers live in a garrison of 5 000 troops garrison duty a garrison town Half the garrison is/are on duty. Word Origin Middle English (in the sense ‘safety, means of protection’): from Old French garison, from garir
‘defend, provide’, of Germanic origin.Extra examples Recognizing the importance of the area, they built a garrison and fortified the town. The Romans maintained a garrison of 5 000 soldiers in the city. The regiment was assigned to garrison duty in the north of the country.