lunacy

[ loo-nuh-see ]

noun

, plural lu·na·cies.

1. insanity; mental disorder.

   Synonyms: craziness, aberration, mania, madness, dementia, derangement

   Antonyms: sanity, rationality

2. intermittent insanity, formerly believed to be related to phases of the moon.

   Antonyms: sanity, rationality

3. extreme foolishness or an instance of it:

   Her decision to resign was sheer lunacy.

   Synonyms: stupidity, folly

4. unsoundness of mind sufficient to incapacitate one for civil transactions: a former legal term.

lunacy

/ ˈluːnəsɪ /

noun

1. (formerly) any severe mental illness
2. foolishness or a foolish act

Word History and Origins

Origin of lunacy¹

First recorded in 1535–45; lun(atic) + -acy

Example Sentences

Instead, drains and pipes carry it away—lunacy, Yu thinks, in places with water shortages.

From MIT Technology Review

It was the kind of rampage mounted by a physician who meets lunacy and delusion with quiet scientific truth.

From The Daily Beast

Charles Manson turned retribution for a drug burn into a shaggy dog story of multi-night massacres, lunacy and a race war he was hoping to kick off.

From Ozy

This effort to prevent the IRS from cracking down on wealthy tax cheats is being sold in language that echoes the lurid lunacy of the Obama years.

From Washington Post

Today the island is called Roosevelt Island, and there are no more lunatics, though there is some degree of lunacy, especially in the waning days of the pandemic.

From Washington Post

I was never sure whether this was phlegm or the onset of lunacy.

From The Daily Beast

Every one of those theories seems like the kind of googly-eyed lunacy only the fringiest fringe-dwellers would believe.

From The Daily Beast

When that woman is Kate Middleton, debate turns into utter lunacy.

From The Daily Beast

Here are 24 short stories, each quintessentially quirky and, some would think, touched by lunacy.

From The Daily Beast

Sometimes, especially during the Faith years, I felt close to lunacy.

From The Daily Beast

Francis le Moine, an excellent French painter, ran himself through with a sword in a fit of lunacy.

From Project Gutenberg

I have been collecting some most valuable information on (looking round at them) lunacy in the—er—county of Devonshire.

From Project Gutenberg

But he is quite a Michelet; the general views, and such a piece of character painting, excellent; but his method sheer lunacy.

From Project Gutenberg

Our whole scheme of things indeed is so mixed, that the wonder only is we are not all in a state of chronic lunacy.

From Project Gutenberg

Lunacy had always been, and remained, a ground of exception from the prohibition to grant outdoor relief.

From Project Gutenberg

Related Words

• absurdity
• folly
• foolishness
• idiocy
• insanity
• mania
• silliness
• stupidity