Have a loose screw Meaning in English
expression
Definition
This is an informal way to say someone behaves strangely or might be a little bit crazy, as if their mind is not working quite right.
Usage & Nuances
This is informal and mildly humorous—used among friends, not in formal settings. Commonly used as "He/She has a loose screw" or "You have a loose screw." It usually suggests eccentricity, not serious mental illness. Don't use it to describe someone with serious psychological conditions.
Example Sentences
I think Tom has a loose screw because he talks to his plants every day.
basic
Mary must have a loose screw to wear a coat in summer.
basic
People say my uncle has a loose screw because he collects rubber ducks.
basic
You seriously have a loose screw if you think that's a good idea.
natural
Don't listen to him—he has a loose screw sometimes.
natural
My brother's always coming up with wild plans. I guess he just has a loose screw.
natural