lunacy
Americannoun
plural
lunacies-
insanity; mental disorder.
- Synonyms:
- aberration, mania, madness, craziness, dementia, derangement
- Antonyms:
- sanity, rationality
-
intermittent insanity, formerly believed to be related to phases of the moon.
- Antonyms:
- sanity, rationality
-
extreme foolishness or an instance of it.
Her decision to resign was sheer lunacy.
-
unsoundness of mind sufficient to incapacitate one for civil transactions: a former legal term.
noun
-
(formerly) any severe mental illness
-
foolishness or a foolish act
Etymology
Origin of lunacy
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
In the case of “Nirvanna the Band,” I assume the answer to the second question at some point becomes “no,” but it’s all done with a very persuasive mix of vérité style and can-do lunacy.
From The Wall Street Journal • Feb. 12, 2026
Beware the three Ls: leverage, liquidity and lunacy.
From MarketWatch • Nov. 7, 2025
The company’s commedia dell’arte-style shenanigans have a natural elasticity but farcical lunacy snaps when stretched too far.
From Los Angeles Times • Sep. 5, 2025
With a show like “And Just Like That,” faith in the series’ future is spun out of pure lunacy.
From Salon • Jul. 15, 2025
Both of them knew that it was lunacy.
From "1984" by George Orwell
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
