Green’s Dictionary of Slang

1. constr. with the, a guinea.

1787

Harris’s List of Covent-Garden Ladies 60: [She] cares not how much she drains him of his liquid treasure, but will be content with one piece of the solid.

2. (UK tramp) the road.

1984

Partridge DSUE (8th edn) 1112/2: [...] C.20.

3. (US Und.) a trustworthy fellow criminal or prison inmate.

1927

H. Yenne ‘Prison Lingo’ in AS II:6 280: Two birds (men) solids of mine (true pals, who will not tell) meet in Chi. (Chicago).

4. (US black) a favour, usu. in phr. do (someone) a/the solid, to perform a favour.

a.1964		‘Honky-Tonk Bud’ in D. Wepman et al. Life (1976) 55: Say, you look sick, like you need a fix, / Perhaps I can do some solids for you.
1973		Eble Campus Sl. Mar. 1: Do me a solid – Do me a favor.
1976		R. Price Blood Brothers 119: If I ever got like that, and I asked you to check me out, would you do me the solid?
1982		W. Safire What’s The Good Word? 83: The help would be forthcoming in light of the fact that you did me a ‘solid’ (a favor).
1990		(con. early 1950s) J. Ellroy L.A. Confidential 393: Give me an answer on this, and if I like it I’ll owe you a solid.
1997		(con. 1970s) G. Pelecanos King Suckerman (1998) 254: Tate did me one big solid today.
2003		Simon & Pelecanos ‘Bad Dreams’ Wire ser. 2 ep. 11 [TV script] Do yourself a solid here, Mike.
2004		A. Mansbach ‘Crown Heist’ in Brooklyn Noir 128: Do me a solid and mind the store, bro.
2012		G. Pelecanos (con. 1972) What It Was 172: The Rosens did you a solid by hiring you.
2017		D. Winslow The Force [ebook] ‘Do me a solid, though. Give Levin an assist’.
2020		D. Winslow ‘Sunset’ in Broken 202: ‘Duke kasmajian owes you a solid’.

5. (US drugs/prison) of money, cash (not notes).

2023

Rayman & Blau Riker’s 182: They wanted cash. I had cash. Get on the phone, ‘Yo, I need five solid.’ Solid means cash.