have a loose screw

have a loose screw

To be or seem particularly silly, eccentric, crazy, or mentally unstable. (Also written as "have a screw loose.") That guy on the corner must have a loose screw or something because he's been standing out there yelling obscenities at passersby all morning. My old Uncle Pete has a few loose screws, but he's a really nice guy. What the hell's the matter with you? Do you have a screw loose, or what?
See also: have, loose, screw
Farlex Dictionary of Idioms.

have a loose screw

verb
See have a screw loose
See also: have, loose, screw
McGraw-Hill's Dictionary of American Slang and Colloquial Expressions
See also:
  • have a screw loose
  • screw loose, to have a
  • have got a loose screw
  • have got a screw loose
  • loo
  • have a few loose marbles
  • with a loose screw
  • with a screw loose
  • screw (something) into (something)
  • screw into