The Collaborative International Dictionary of English v.0.48:

Dorm \Dorm\, n.
   a dormitory. [College slang.]
   [PJC]

WordNet (r) 3.0 (2006):

dorm
    n 1: a college or university building containing living quarters
         for students [syn: dormitory, dorm, residence hall,
         hall, student residence]

Moby Thesaurus II by Grady Ward, 1.0:

25 Moby Thesaurus words for "dorm":
   boardinghouse, dormitory, doss house, drowse, fleabag, flophouse,
   guest house, hospice, hostel, hostelry, hotel, inn, lodging house,
   ordinary, pension, posada, pub, public, public house, roadhouse,
   rooming house, slumber, snooze, snoozle, tavern