have a screw loose
In real, traceable use. Part of the curated seed collection; community review is coming.
Meaning · English
To be insane, irrational, or eccentric.
Register: slang
Where it’s used:
Used
American English
Examples
Richard, glorious in new livery, [...] went with his sad message, first to the church and then to the banqueting-hall in Albemarle Street. "Not any wedding?" said the head-waiter at the hotel. "I knew they was folks as would have a screw loose somewheres. [...]"
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 “have a screw loose” mean?
To be insane, irrational, or eccentric.
Is “have a screw loose” formal or informal?
have a screw loose is generally slang.