The Collaborative International Dictionary of English v.0.48:

Barmy \Barm"y\ (b[aum]rm"[y^]), a.
   Full of barm or froth; in a ferment. "Barmy beer." --Dryden.
   [1913 Webster]

WordNet (r) 3.0 (2006):

barmy
    adj 1: marked by spirited enjoyment [syn: zestful, yeasty,
           zesty, barmy]
    2: informal or slang terms for mentally irregular; "it used to
       drive my husband balmy" [syn: balmy, barmy, bats,
       batty, bonkers, buggy, cracked, crackers, daft,
       dotty, fruity, haywire, kooky, kookie, loco,
       loony, loopy, nuts, nutty, round the bend, around
       the bend, wacky, whacky]

Moby Thesaurus II by Grady Ward, 1.0:

58 Moby Thesaurus words for "barmy":
   balmy, bananas, bats, batty, beany, bonkers, buggy, bughouse, bugs,
   crackers, cuckoo, daffy, diastatic, dippy, dotty, enzymic,
   fermenting, flaky, flipped, foam-flecked, foamy, freaked-out,
   frothy, fruitcakey, fruity, gaga, goofy, haywire, heady,
   just plain nuts, kooky, lathery, leavening, loony, loopy, nuts,
   nutty, off the hinges, off the track, off the wall, potty, raising,
   round the bend, screwball, screwballs, screwy, slaphappy,
   soapsuddy, soapsudsy, soapy, spumose, spumous, spumy, suddy, sudsy,
   wacky, working, yeasty