Green’s Dictionary of Slang

1. superficial, flashy, meretricious.

1987		EPMD ‘You Gots To Chill’ 🎵 To the average MC I’m known as The Terminator. / Funky beat maker, new jack exterminator.
2004		N. Kelley ‘The Code’ in Brooklyn Noir 187: He had the aura of a champion boxer, a new jack Muhammad Ali.
2010		Codella and Bennett Alphaville (2011) 293: This new jack nigga all muscled up and shit just outta jail a few months.

2. in tune with the contemporary young black culture.

1991		Cooper & Wright New Jack City [film script] I need cops that know these streets. I need new jack cops to take down a new jack gangster.
1992		N. George ‘Cool vs. Chilly’ in Buppies, B-Boys, Baps and Bohos (1994) 72: The new jack swing of Teddy Riley and Tammy Lucas on ‘Is It Good to You.’.
2001		Source Aug. 154: Whether you’re an old-school biker or a new-jack rider, we’ve got bikes that’ll get the most burn this summer.

3. naive, unaccomplished; thus New Jack City, the epitome of the unfledged novice.

2010		Codella and Bennett Alphaville (2011) 221: I don’t want some new jack white kid rookie shooting me in the back.
2011		G. Hayward Corruption Officer [ebk] cap. 10: The day went on with me doing more new jack shit.
2023		Rayman & Blau Riker’s 14: I must have looked like New Jack City [...] ‘Yo, punk white boy from Long Island! [...] New Jack motherfucker!’.