plural lunacies
1
dated
a
b
: intermittent insanity once believed to be related to phases of the moon
2
: wild foolishness : extravagant folly
3
: a foolish act
Synonyms
Examples of lunacy in a Sentence
Quitting her job was lunacy.
His idea was considered total lunacy.
Recent Examples on the Web
The cast try their best to keep up with such lunacy.
—
Jon O'Brien, IndieWire, 16 Jan. 2025
There’s always been pushback against anti-immigrant lunacy here.
—
Gustavo Arellano, Los Angeles Times, 30 Jan. 2025
To suggest that anyone who vaccinates their kids doesn’t love them is a whole new level of lunacy.
—
Dr. Sanjay Gupta, CNN, 29 Jan. 2025
At its peak, it’s got some adrenalin-pumping lunacy that’s admirable.
—
Brian Tallerico, Vulture, 10 Dec. 2024
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Word History
First Known Use
1541, in the meaning defined at sense 1a
Dictionary Entries Near lunacy
Cite this Entry
“Lunacy.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/lunacy. Accessed 15 Feb. 2025.
Kids Definition
Medical Definition
lunacy
noun
lu·na·cy
ˈlü-nə-sē
plural lunacies
dated
: mental illness
also
: intermittent mental illness once believed to be related to phases of the moon
More from Merriam-Webster on lunacy
Nglish: Translation of lunacy for Spanish Speakers
Britannica English: Translation of lunacy for Arabic Speakers
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