[1] : The Collaborative International Dictionary of English v.0.48

wacke \wack"e\, wacky \wack"y\, n. g. wacke, mhg. wacke a large
   stone, ohg. waggo a pebble. geol.
   a soft, earthy, dark-colored rock or clay derived from the
   alteration of basalt.
   1913 webster

[2] : WordNet (r) 2.0

wacky
     adj 1: pungent adjectives of disesteem; "gave me a cockamamie
            reason for not going"; "wore a goofy hat"; "a silly
            idea"; "some wacky plan for selling more books" syn:
            cockamamie, cockamamy, goofy, sappy, silly,
            whacky, zany, unreasonable
     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, whacky
     also: wackiest, wackier
see also:
cockamamie cockamamy goofy sappy silly whacky 
zany unreasonable 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 wackiest wackier 

[3] : Moby Thesaurus II by Grady Ward, 1.0

119 moby thesaurus words for "wacky":
   abnormal, absurd, anomalous, apish, asinine, balmy, bananas, barmy,
   bats, batty, beany, befooled, beguiled, besotted, bonkers,
   brainless, buffoonish, buggy, bughouse, bugs, cockeyed, cracked,
   crackers, crank, crankish, cranky, crazed, crazy, credulous,
   crotchety, cuckoo, daffy, daft, dazed, demented, deranged, deviant,
   deviative, different, dippy, divergent, dizzy, doting, dotty, dumb,
   eccentric, erratic, exceptional, fatuitous, fatuous, fey, flaky,
   flipped, fond, fool, foolheaded, foolish, freaked-out, freakish,
   fruitcakey, fruity, fuddled, funny, futile, gaga, goofy, gulled,
   harebrained, haywire, idiocratic, idiosyncratic, idiotic, imbecile,
   inane, inept, infatuated, insane, irregular, just plain nuts,
   kinky, kooky, loony, loopy, lunatic, mad, maggoty, maudlin,
   moronic, nuts, nutty, odd, oddball, off the hinges, off the track,
   off the wall, peculiar, potty, preposterous, queer, quirky,
   round the bend, sappy, screwball, screwballs, screwy, senseless,
   sentimental, silly, singular, slaphappy, strange, stupid,
   thoughtless, twisted, unconventional, unnatural, wet, whimsical,
   witless

Wacky >> W Words
Wacky, definition of term: Wacky
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