The Collaborative International Dictionary of English v.0.48:

Galoot \Ga*loot"\, n.
   A noisy, swaggering, or worthless fellow; a rowdy. [Slang, U.
   S.]
   [1913 Webster]

WordNet (r) 3.0 (2006):

galoot
    n 1: a disreputable or clumsy man

Moby Thesaurus II by Grady Ward, 1.0:

27 Moby Thesaurus words for "galoot":
   asshole, bloke, boob, booby, buck, chap, chump, cuss, ding-a-ling,
   dingbat, dingdong, fellow, gee, gent, goof, guy, jerk, jerk-off,
   klutz, man, mutt, prize sap, sap, saphead, sawney, schlemiel,
   skate