wear it, v. — Green’s Dictionary of Slang

wear it v.

1. (UK Und.) to be accused of becoming an informer.

1812		Vaux Vocab. of the Flash Lang. in McLachlan (1964) 278: wear it to wear it upon a person, (meaning to wear a nose, or a conk,) is synonymous with nosing, conking, splitting, or coming it, and is merely one of those fanciful variations so much admired by flash people.
1823		Egan Grose’s Classical Dict. of the Vulgar Tongue.

2. (US Und.) to take the blame for a crime even when not actually guilty.

1937

J. Curtis You’re in the Racket, Too 40: There’s a chance he’ll wear it.

wear it upon (v.) [‘it’ is the nose, i.e. nose n. (1)]

(UK Und.) to inform against.

1812		Vaux Vocab. of the Flash Lang. in McLachlan (1964) 278: wear it to wear it upon a person, (meaning to wear a nose, or a conk,) is synonymous with nosing, conking, splitting, or coming it, and is merely one of those fanciful variations so much admired by flash people.
1823		Egan Grose’s Classical Dict. of the Vulgar Tongue.