Synonyms for Brainless:

adj.

all (adjective)
headless.
foolish (adjective)
dotty, dopey, blockheaded, inane, meat-headed, cretinous, foolish, asinine, moronic, bone-headed, absurd, crackpot, ignorant, imbecilic, dumb, loony, chuckle-headed, idiotic, half-witted, dim-witted, knuckle-headed, goofy, doltish, nitwit, blithering, lame-brained, crazy, nonsensical.
idiotic (adjective)
thoughtless, senseless, dumb, foolish, mindless, witless, silly.
ignorant (adjective)
illiterate, uneducated, simple, unlearned, ignorant, empty-headed, unintelligent, uninformed, mindless, foolish.
senseless (adjective)
silly.
thoughtless (adjective)
fatuous, vacuous, mindless, empty-headed, unoccupied, thoughtless, illogical, unthinking, vacant, inane, unreasonable, unthoughtful, blank.
witless (adjective)
witless.

n.

insensate, silly, simple-minded, planned, ability, Weak-minded, senseless, witless. brainless (noun)
headless, unintelligent.

Other synonyms:

simple-minded, witless. Weak-minded. senseless. insensate. Other relevant words:
witless, silly, headless, insensate, senseless, Weak-minded, simple-minded.

Usage examples for brainless

  1. Especially he had despised the young men as brainless cowards in regard to their views of women and conduct toward them. – The Complete Project Gutenberg Works of George Meredith by George Meredith
  2. I am fit only to be the wife of an idle brainless man, with money and a title, ' she said, in extreme self- contempt. – The Complete Project Gutenberg Works of George Meredith by George Meredith