Definition of lunatic:
meshuga, dwarf, loco, unhinged, ding-a-ling, barmy, haywire, unearthly, loon, hunchback, gaga, nuts, wacko, unwise, buggy, madwoman, idiotic, loony, loony tunes, sane, foolish, wise, swashbuckler, harum-scarum, bedlam, loopy, absurd, bonkers, risky, preposterous, cripple, fruity, mentally ill, moronic, jerky, madman, half-witted, softheaded, dippy, cabbage, unsafe, witless, silly, nutjob, imbecile, damaging, sappy, dotty, nonsensical, cracked, hazardous, bananas, weak-minded, zany, fool, wud, disordered, cockeyed, brainsick, humpback, bughouse, backward, weirdie, screwy, cranky, screwball, space cadet, fire-eater, crackers, madcap, off, lunkheaded, dingbat, wacky, asinine, featherheaded, imbecilic, crazed, bubbleheaded, ruinous, fatuous, daft, simpleminded, oddball, knowledge, scatty, tomfool, touched, hothead, ability, harebrained, weirdo, unsound, injurious, headcase, crackbrained, disastrous, insane, cuckoo, maniac, dangerous, non compos mentis, eccentric, mental, distraught, harmful, bats, senseless, moonstruck, brainless, balmy, perilous, daffy, certifiable, half-baked, daredevil, wrong, inept, oddity, dopey.
- foolish (part of speech: adjective)
- lunatic (part of speech: noun)
- insane (part of speech: adjective)
- "The Spoilers of the Valley", Robert Watson.
- "What Maisie Knew", Henry James.
- "The Turnstile", A. E. W. (Alfred Edward Woodley) Mason.