cuckoo
In real, traceable use. Part of the curated seed collection; community review is coming.
Meaning · English
Crazy; not sane.
Register: slang
Where it’s used:
Used
American English
Examples
I think I'm going cuckoo!
Usage example from English Wiktionary (CC BY-SA 4.0, retrieved 2026-07-30)
Sources & notes
Adapted from English Wiktionary (CC BY-SA 4.0, retrieved 2026-07-30 via kaikki.org).
Common questions
What does “cuckoo” mean?
Crazy; not sane.
Is “cuckoo” formal or informal?
cuckoo is generally slang.