1. (adj)idiot, imbecile, cretin, moron, changeling, half-wit, retard a person of subnormal intelligence Synonyms: nitwit, moron, doofus, cretin, dimwit, idiot, changeling, retard, imbecile, half-wit Antonyms: precocious
2. (adj)imbecile, imbecilic, idiotic having a mental age of three to seven years Synonyms: ludicrous, absurd, laughable, nonsensical, idiotic, preposterous, ridiculous, cockeyed, derisory, imbecilic, imbecile, crackbrained Antonyms: precocious