ENGLISH
REFERENCE

lunacy

n.
C1 Advanced US //ˈɫunəsi// UK //lˈuːnəsi// lu·na·cy

n. a state of being very foolish or crazy. You use this to describe a situation that makes no sense or a person who is acting like a mad person.

n. a state of extreme foolishness or insanity; a lack of reason or logic. Often used to describe irrational behavior or policies that defy common sense.


SIMPLE

The plan to build a bridge over the river was pure lunacy.

CONTEXTUAL

The sudden decision to cancel the entire season was seen as a complete lunacy by the fans and the board.

COMPLEX

The historian argued that the war was a tragic lunacy, driven by a combination of personal grudges and a failure to understand the geopolitical landscape.

Synonyms
Origin

From lunatic + -cy.

© 2026 English Reference