have a screw loose
- (slang) To be insane, irrational, or eccentric.
- I think old Mr. Jacobs has a screw loose; he keeps trying to feed his cats bird seed.
1873, Anthony Trollope, chapter 69, in The Eustace Diamonds:
- Richard, glorious in new livery, . . . went with his sad message, first to the church and then to the banqueting-hall in Albemarle Street. "Not any wedding?" said the head-waiter at the hotel. "I knew they was folks as would have a screw loose somewheres."
1916, Eleanor H. Porter, chapter 22, in Just David:
- "You know he really has got a screw loose in his head somewheres, an' there ain't any one but what says he's the town fool, all right."
- 2010 July 16, Alessandra Stanley, "Television: Back to Work for ‘Mad Men’," New York Times (retrieved 16 June 2016):
- Pete Campbell (Vincent Kartheiser) would be just another irritating office brown-noser, a prep school Sammy Glick, except that he too has a screw loose and a mystical rapport with firearms.
to be insane, irrational, or eccentric