Synonyms of lunacy

lunacy

noun

ˈlü-nə-sē 

1

as in insanity

a foolish act or idea

you want to sneak into the building after the alarm is set—what lunacy!

Synonyms & Similar Words

• insanity
• idiocy
• absurdity
• madness
• stupidity
• imbecility
• inanity
• bêtise
• foppery
• folly
• asininity
• foolery
• craziness
• fatuity
• absurdness
• buffoonery
• tomfoolery
• blunder
• nonsense
• witlessness
• foolishness
• twaddle
• senselessness
• inaneness
• shenanigan(s)
• drivel
• monkeyshine(s)
• bungle
• flub
• howler
• humbug
• goof

Antonyms & Near Antonyms

• wisdom
• discretion
• prudence
• sagacity
• inspiration
• forethought
• brainstorm

2

as in dementia

a serious mental disorder that prevents one from living a safe and normal life

the judge ruled that the lunacy of the accused made him incompetent to stand trial

Synonyms & Similar Words

• dementia
• insanity
• madness
• hysteria
• schizophrenia
• instability
• paranoia
• mania
• rage
• derangement
• aberration
• delusion
• psychosis
• frenzy
• neurosis
• irrationality
• delirium
• unreasonableness
• obsession
• abnormality
• phobia
• hallucination
• senile dementia
• unsoundness
• hypomania
• monomania
• hallucinosis
• dementedness

Antonyms & Near Antonyms

• sanity
• mind
• rationality
• lucidity
• reasonableness
• saneness
• normality
• soundness
• reasonability
• rationalness

3

as in madness

lack of good sense or judgment

was it desperation or lunacy that caused him to quit his job and move to California without any plan for what to do when he got there?

Synonyms & Similar Words

• insanity
• madness
• absurdity
• simplicity
• craziness
• foolishness
• wackiness
• zaniness
• daftness
• fatuousness
• inanity
• silliness
• preposterousness
• imbecility
• nuttiness
• unwisdom
• dottiness
• witlessness
• stupidness
• stupidity
• asininity
• folly
• brainlessness
• idiocy
• fatuity
• nonsensicalness
• balminess
• senselessness
• irrationality
• obtuseness
• dippiness
• dumbness
• dullness
• ridiculousness
• feeblemindedness
• unreasonableness
• slowness
• mindlessness
• simpleness
• dopiness
• oafishness
• simplemindedness
• denseness
• doltishness
• kookiness
• weirdness
• fallacy
• ludicrousness
• vacuity
• gormlessness
• dim-wittedness
• laughableness

Antonyms & Near Antonyms

• sanity
• wisdom
• sagacity
• prudence
• soundness
• rationality
• validity
• reasonableness
• sapience
• sensibleness
• logicality
• sagaciousness
• reasonability
• insight
• perception
• sageness
• discernment
• logicalness
• rationalness
• percipience

Example Sentences

Recent Examples of lunacy

After all, there’s ample lunacy to be found on the left and the right these days. — Clarence Page, Chicago Tribune, 30 Mar. 2026

Once upon a time, the idea of a baseball team allowing most of its games to be broadcast on television was lunacy. — Ken Sugiura, AJC.com, 24 Feb. 2026

Because it’s invariably attached to the idea of some kind of lunacy. — Zack Sharf, Variety, 3 Nov. 2025

Because it's invariably attached to the idea of some kind of lunacy. — Mekishana Pierre, Entertainment Weekly, 3 Nov. 2025