Green’s Dictionary of Slang

1. (drugs) in possession of drugs, esp. for dealing, selling; or money to obtain drink or drugs.

1935		A.J. Pollock Und. Speaks n.p.: I’m holding, I have dope to sell.
1953		‘William Lee’ Junkie (1966) 26: The connection was here about ten minutes ago. This character’s holding, but he won’t turn loose of any.
1963		J. Rechy City of Night 295: Shes holding [...] and I just cant handle her myself.
1977		A. Hoffman Property Of (1978) 91: You’re not holding now? You hung me up today and now you don’t even have any shit?
1987		(con. c.1967) J. Ferrandino Firefight 145: Fluett wants you to burn shit tonight, [...] Are you holding?
1994		I. Welsh ‘Stoke Newington Blues’ in Acid House 35: – You holdin? [...] – Like fuck. Ah’m here tae score.
1999		P. Kawana Attack of the Skunk People 87: Shara .. . flicked through her address book, trying to suss out which of her friends would be holding.
2001		D. Looser Boobslang [U. Canterbury D.Phil. thesis] 88/2: holding n. a store of contraband, usually drugs.
2002		E. Damerson in Dusted Mag. at Trikont.com 🌐 Perfect for your next crosstown crawl, whether you’re holding or not. And one of the many, many cherry good, amusingly esoteric collections our pals at Trikont are hawking.
2020		D. Winslow ‘Sunset’ in Broken 209: He’d bet [...] that the guy is holding.

2. (US campus) of dress, attractive.

1987

Eble Campus Sl. Fall 5: holdin’ – attractive, nice-fitting, as applied to clothing: That jacket she has on is holdin’.

3. see hold v.¹ (1)