Green’s Dictionary of Slang

1. to offer an advantage to.

1931		P. Paul ‘The Madame Plays the Gee-Gees’ in Gun Molls Sept. 🌐 Fingers that could spot the best [...] cold-card artist [...] whatever he liked, and beat him at his own game.
1935		(con. 1920s) J.T. Farrell Judgement Day in Studs Lonigan (1936) 540: Your old man could spot both of you a good-sized pint and still watch you pass out.
1946		J.F. Powers ‘Prince of Darkness’ in Accent (Winter) 95: I’ll lay you even money the Sox make it three straight in Philly and spot you a run a game to boot.
1950		Goldin et al. DAUL 203/2: Spot, v. [...] 2. To concede an advantage to an opponent.
1982		G.V. Higgins Patriot Game (1985) 57: This is a guy that couldn’t spell cat unless you spotted him the c and the a.

2. to advance on credit, to treat.

1977		C. Hope Ducktails in Gray Theatre Two (1981) 38: sooliman: Twenty-five shillings. jimmie: Don’t tune me skraal. Spot you a quid for it, ek se.
2007		C. Goffard Snitch Jacket 172: Spot me a C-note?
2010		Codella and Bennett Alphaville (2011) 264: Old friends, bartenders, and starstruck college kids alike were happy to spot him a twenty.
2019		N. Walker Cherry 217: I asked him to spot me one [Oxycontin] for a day or two. He said okay.
2022		J. Hannaham Didn’t Nobody Give a Shit 176: ‘I can spot you honey. I’m making it’.