be not right in the head

be not right in the head

To be mentally unwell or unstable. The term can be used both literally and hyperbolically. Tim has been behaving very erratically lately, so I'm afraid that he's not right in the head. Oh, Liz is not right in the head if she thinks that plan will work!
See also: head, not, right
Farlex Dictionary of Idioms.
See also:
  • go crazy
  • everyone and their mother
  • chain (someone or something) to (something)
  • chain to
  • everyone and their dog
  • everyone and their brother
  • everyone and his mother
  • everybody and their mother
  • everybody and his mother
  • everybody and their brother