Green’s Dictionary of Slang

1. (Irish) any form of mental deficiency.

1987

(con. 1920s) L. Redmond Emerald Square 177: Lil whispered to me that he had had a nervous breakdown, there was a ‘little want’ in him.

2. (US police) a charge, a ‘wanted’ notice.

1945		L. Hoban ‘Time to Kill’ Crack Detective Jan. 🌐 I’ve been looking for a guy — a guy that had a want on him.
1971		E.E. Landy Underground Dict. (1972).
1977		J. Sayles Union Dues (1978) 29: Maybe we scoop him [...] Maybe he’s got a want on. We should call in.
1984		J. Ellroy Because the Night 199: [T]he operator came back on the air with her information—FHM 363—No wants; no warrants.
1999		J. Maple Crime Fighter 61: I picked Rondell up on a want.