Green’s Dictionary of Slang

1. (US) a nickel, a 5-cent coin.

1914		E. Wittmann ‘Clipped Words’ in DN IV:ii 120: jit, from jitney. ‘We went to the second jit show.’.
1916		J. Lait ‘Charlie the Wolf’ in Beef, Iron and Wine (1917) 55: Where could he go? He didn’ have a jit. He couldn’ go to no theayter, that costs dough.
1926		J. Black You Can’t Win (2000) 248: A ‘flop’ on the bare floor for a ‘jit,’ as the Southern negro affectionately calls his nickel.
1934		H. Roth Call It Sleep (1977) 303: I buys a couple o’ franks on a roll fer a jit.
1946		J.E. Dadswell Hey, Sucker 96: jit (short for jitney) five cents.
1962		Ragen & Finston World’s Toughest Prison 805: jit – A nickel.
1991		(con. 1920s) O.D. Brooks Legs 196: I [...] picked the jit out of the return slot.

2. (US) a black person.

1931		Irwin Amer. Tramp and Und. Sl. 110: Jit. [...] A negro or, more usually, a negress, and seemingly a term of derision, indicative of cheapness.
1944		Mencken ‘Designations for Colored Folk’ in AS XIX:3 174: The DAE does not list such vulgar synonyms for Negro as [...] jit.
1983		I.L. Allen Lang. of Ethnic Conflict 50: Status Diminution: jit [especially, fem. From jitney, a fivecent piece, hence a thing of small value].

3. (US black, also jitt) a derog. term for a young person, a foolish person.

1997–2000		College Sl. Research Project (Cal. State Poly. Uni., Pomona) 🌐 Jit (noun) A young’un; a newbie.
2000		Ebonics Primer at www.dolemite.com 🌐 jitt Definition: meaningless people, usually younger, who talk too much or are just plain annoying. Example: I am gonna ride out, the house is full of jitts!
2012		NY Times 12 Mar. 🌐 If somebody says ‘bro you suck at football’ you would respond ‘Jit creep’.