WordNet (r) 3.0 (2006):

body odor
    n 1: malodorousness resulting from a failure to bathe [syn:
         body odor, body odour, B.O.]

Moby Thesaurus II by Grady Ward, 1.0:

39 Moby Thesaurus words for "body odor":
   BO, bad breath, bad smell, beaded brow, beads of sweat, cold sweat,
   diaphoresis, exudate, exudation, fetidity, fetidness, fetor,
   foul breath, foul odor, frowst, graveolence, halitosis,
   honest sweat, lather, malodor, mephitis, miasma, nidor,
   noxious stench, offensive odor, perspiration, perspiration odor,
   reek, reeking, rotten smell, stench, stench of decay, stink,
   streams of sweat, sudor, sudoresis, sweat, swelter, water