WordNet (r) 3.0 (2006):

haywire
    adj 1: 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]
    2: not functioning properly; "something is amiss"; "has gone
       completely haywire"; "something is wrong with the engine"
       [syn: amiss(p), awry(p), haywire, wrong(p)]
    n 1: wire for tying up bales of hay

Moby Thesaurus II by Grady Ward, 1.0:

78 Moby Thesaurus words for "haywire":
   amiss, askew, awry, balmy, bananas, barmy, bats, batty, beany,
   bonkers, broken, buggy, bughouse, bugs, cockeyed, convulsed,
   crackers, cuckoo, daffy, deranged, dippy, disarranged, discomfited,
   discomposed, disconcerted, dislocated, disordered, disorderly,
   disorganized, disturbed, dotty, flaky, flipped, freaked-out,
   fruitcakey, fruity, gaga, goofy, in disorder, in disrepair,
   inoperative, just plain nuts, kooky, loony, loopy, misplaced, nuts,
   nutty, off the hinges, off the track, off the wall, on the blink,
   on the fritz, out of commission, out of condition, out of gear,
   out of joint, out of kelter, out of kilter, out of order,
   out of place, out of repair, out of tune, out of whack, perturbed,
   potty, roily, round the bend, screwball, screwballs, screwy,
   shuffled, slaphappy, turbid, turbulent, unsettled, upset, wacky