screw-loose

listen to the pronunciation of screw-loose
Английский Язык - Английский Язык
not behaving normally
have a screw loose
To be insane or irrational

I think old Mr. Jacobs has a screw loose; he keeps trying to feed his cats bird seed.

have a screw loose
(deyim) Be silly or eccentric
has a screw loose
is a little crazy, not totally normal