have a screw loose

screw definition

1. tv. & in.
   to copulate [with] someone. (Very old. Usually objectionable.) : The sailor wanted to screw somebody bad.
2. tv. & in.
   to cheat or deceive someone. : You can count on somebody screwing you at a traveling carnival.
3. n.
   an act of copulation. (Usually objectionable.) : The sailor said he needed a good screw.
4. n.
   a person with whom one can copulate. (Usually objectionable.) : His teeth are crooked and his hands are callused, but he's a good screw.
5. n.
   a jailer. (Very old. Underworld.) : See if you can get the screw's attention.