Synonyms of off-the-wall

1 Syllable

mad, wrong, wild

2 Syllables

wacky, crazy, kooky, silly, jovial, raving, foolish, distraught, festal, stupid, quirky, loony, nutty, oddest, absurd, flaky, freaky, brainless, mindless, unsound, specious, odder, jollying

3 Syllables

unstable, disjointed, sophistic, insane, fallacious, invalid, unwise, unthinking, delirious, demented, aberrant, reasonless

4 Syllables

irrational, ridiculous, nonsensical, unreasoning, preposterous, injudicious, cockamamie, disconnected, conversable, incoherent

5 Syllables

unreasonable, uncustomary