hall rat
n.— «Hall rat—A mid who stays in Bancroft Hall all weekend; someone with no social life.» —“A look at the lingo used by the mids; Source: Brief Points: An Almanac for Parents and Friends of U.S. Naval Academy Midshipmen” in U.S. Naval Academy The Capital (Annapolis, Md.) May 22, 2005. (source: Double-Tongued Dictionary)