Synonyms of brainless

1 Syllable

dumb, dull

2 Syllables

tomfool, silly, sillier, duller, ditzy, foolish, fatuous, witless, thoughtless, stupid, doltish, giddy, dullest, loopy, mindless, silliest

3 Syllables

stupidest, off-the-wall, softheaded, half-baked, senseless, moronic, thick-headed

4 Syllables

boneheaded, irrational, imbecilic, muddleheaded, empty-headed, featherbrained, imbecile, unreasoning, cockamamie, simpleminded, cockamamy

5 Syllables

unintelligent, anencephalic, anencephalous