dormitory (n.)

mid-15c., "place, building, or room to sleep in," originally of a monastery or nunnery, from Latin dormitorium "sleeping place," from dormire "to sleep" (see dormant). From the vernacular Old French form dortor Middle English had the word earlier as dortour (c. 1300). Old English had slæpern "dormitory," with ending as in barn. As "residence hall of a college or university" by 1718.