Definition of lunatic
- a lunatic asylum
- a lunatic idea
- lunatic behavior
He hatched a lunatic plot to overthrow the government.
another of his lunatic ideas
These example sentences are selected automatically from various online news sources to reflect current usage of the word 'lunatic.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.
absurd, asinine, balmy, brainless, cockeyed, crackpot, crazy, cuckoo, daffy, daft, dippy, dotty, fatuous, featherheaded, fool, foolish, half-baked, half-witted, harebrained, inept, insane, jerky, kooky (also kookie), loony (also looney), lunkheaded, mad, nonsensical, nutty, preposterous, sappy, screwball, senseless, silly, simpleminded, stupid, tomfool, unwise, wacky (also whacky), weak-minded, witless, zany;
airheaded, birdbrained, brain-dead, chowderheaded, chuckleheaded, clueless, dense, dim, dim-witted, doltish, dopey (also dopy), dorky [slang], dull, dumb, dunderheaded, empty-headed, fatuous, feebleminded, idiotic (also idiotical), imbecile (or imbecilic), knuckleheaded, lamebrain (or lamebrained), mindless, moronic, oafish, obtuse, opaque, pinheaded, simple, slow, slow-witted, soft, softheaded, thoughtless, thick, thickheaded, unintelligent, vacuous, witless;
out to lunch;
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