Green’s Dictionary of Slang

stuff, the n.

1. what one wants, the ideal; usu. in phr. that’s the stuff

[UK]Fielding Tom Jones (1959) 280: ‘Here,’ said he, taking some dice out of his pockets, ‘here’s the stuff. Here are the implements; here are the little doctors which cure the distempers of the purse.’.
[Aus]N.-Y. National Advocate 13 July 2/4: One of the leaders of this gang of counterfeiters waited on Mr. Warner, and showed him some specimens of notes purporting to be on the Washington and Warren bank, and observed, ‘that it was the stuff,’ and offered to see him (Mr. Warner) any amount of the notes.
[US]T. Haliburton Clockmaker II 216: The English all say he wants the clear grit – ain’t got the stuff – no ginger in him.
[US]Ypsilanti Sentinel (MI) 5 May 1/4: I’m never so thirsty aas to drink bad liquor [...] But here’s the stuff’.
[UK]M. Reid Scalp-Hunters II 190: Yez ar sure now it’s the stuff?
[UK]H. Mayhew London Characters 421: A pound of steak with plenty of gravy in it; that’s the stuff to work upon.
[US]A. Pinkerton Mollie Maguires and the Detectives 64: You are not of ‘the stuff,’ I guess! At least, I know I am not!
[US]F. Remington letter 14 Oct. in Splete Sel. Letters (1988) 150: It makes a man look like a grizzly bear and feel like one but its the stuff.
[US]O. Johnson Varmint 53: Isn’t it the stuff.
[US]‘Lord Ballyrot in Slangland’ in Tacoma Times (WA) 11 Nov. 4/4: That guy makes the U.S. mint look like a cofee mill when it comes to turning out the stuff.
[UK]Wodehouse Psmith Journalist (1993) 242: You are, beyond a doubt, supremely the stuff.
[US]E. Anderson Thieves Like Us (1999) 41: There I was down in Florida with [...] a woman that was the stuff.
[US]L. Durst Jives of Dr. Hepcat (1989) 2: And suddenly you know that the stuff is here and this is it. ‘Slay’ me now I don’t want to go another further.
[UK]P. Fordham Inside the Und. 43: But this was the stuff.

2. money.

[UK]Proc. Old Bailey 14 Nov. 106: I said, ‘That is not much to kill a man for’—he said, ‘We thought he had a lot of stuff on him’—‘stuff’ is money in some class of people's mouths.
[Aus]‘G.G.’ Sporting Sketches in Sportsman (Melbourne) (18/10/1898) 5/7: ‘Why, lord lumme! we could git the stuff ’ere [...] like makin’ bally ’ay’.
[UK]London Standard 19 Jan. 3/4: Bee! Ba! Black sheep, have you any cole* [*Cole — the stuff, the stumpy, money].

3. an important (or self-important) person.

[US]R.C. Cruz Straight Outta Compton 69: Billy strolled in late like he was the stuff.

In phrases

that’s the stuff (also that’s the style)

a general term of approval.

Richard of York 1 68: ’Tis good ale [...] but the sack! that’s the stuff, Samson, that’s the stuff! It has a moreish flavour with it, ha! ha!
[UK]Bradford Obs. 27 Jan. 7: Teddy [...] exclaimed — ‘Fwy dhen, dat’s the stuff; and here’s bad luck to him that paid fwhor it!’.
[UK]New Mthly Mag. 94 310: ‘Get out the Cardigan, Jasper,’ said the colonel to the man, who forthwith produced a three-quarters-full black bottle, with the word ‘Brandy,’ in black letters on the ivory label. ‘Ah, that's the stuff!’ exclaimed the colonel.
[[UK]G.F. Northall Folk-Phrases of Four Counties 24: That’s the stuff for trousers. This phrase [...] is now freely used of any good thing].
[US]H. Green Actors’ Boarding House (1906) 90: Now, you’re talkin [...] That’s the stuff!
[UK]T. Burke Limehouse Nights 72: Don’t you worry. Feeling better? That’s the style.
[UK]Marvel 1 Mar. 5: That’s the stuff, old bird!
[US]D. Hammett ‘Dead Yellow Women’ Story Omnibus (1966) 154: ‘Five bucks I spend for this shirt.’ ‘That’s the stuff.’ I applauded his wisdom in investing part of his fan tan profits.
[Aus]X. Herbert Capricornia (1939) 115: That’s the stuff. Do it properly.
[NZ]J. Henderson Gunner Inglorious (1974) 149: Plenty of plonk [...] Aha! That’s the stuff.
[WI]R. Mais Black Lightning (1966) 221: That’s the way to talk, girl, that’s the stuff.
[UK]J.R. Ackerley We Think The World Of You (1971) 41: That’s the stuff!
[Aus]A. Buzo Roy Murphy Show (1973) 103: Morning, Col. Getting any? That’s the stuff.
[US]B. Gutcheon New Girls (1982) 267: ‘That’s the stuff!’ cried the tall voices.