Absurd, Addled, Apish, Asinine, Backward, Balmy, Batty, Beguiled, Besotted, Block, Blockish, Bootless, Boring, Bovine, Brainless, Brute, Brutish, Clod, Cockeyed, Senseless, Sentimental, Silly, Simple, Simpleton, Slow, Sluggish, Stolid, Subnormal, Tedious, Thick, Thoughtless, Tiresome, Torpid, Unimaginative, Uninspired, Unintelligent, Uninteresting, Vacuous, Vapid, Wacky, Wet, Witless, Crass, Crazy, Credulous, Cretinous, Cuckoo, Daffy, Daft, Dazed, Dense, Dim, Dimwit, Dizzy, Dolt, Donkey, Dope, Dopey, Doting, Dozy, Dull, Dullard, Dumb, Dumbbell, Dummy, Dunce, Fat, Fatuous, Flaky, Fond, Fool, Foolhardy, Foolish, Frivolous, Fuddled, Futile, Gaga, Goofy, Gross, Humdrum, Idiot, Idiotic, Ignoramus, Imbecile, Imbecilic, Inane, Inept, Infatuated, Insane, Insipid, Irrational, Irresponsible, Jerky, Laughable, Lightweight, Loon, Loony, Ludicrous, Lumbering, Lumpish, Mad, Maudlin, Mindless, Monotonous, Moron, Moronic, Nincompoop, Ninny, Nitwit, Noddy, Nonsensical, Nutty, Oafish, Obtuse, Opaque, Pinhead, Prosaic, Put, Retarded, Ridiculous, Risible, Screwy