Green’s Dictionary of Slang

1. (US campus) an unpopular, unpleasant person.

1871

L.H. Bagg Four Years at Yale 48: Slick, a loutish fellow, a pill.

2. (orig. US black, also slickie) a smart, charming, fashionable, sophisticated person.

1846		Durivage & Burnham Stray Subjects (1848) 83: A very shrewd Yankee of the Sam Slick school, who fomerly kept a slop-shop in the classic purlieus of Ann street].
1940		‘Digg Mee’ ‘Observation Post’ in N.Y. Age 26 Oct. 10/7: Now, to him, shes never there...Our little ‘slickie’ is like the bear.
c.1943		‘Bill O. Lading’ You Chirped a Chinful!! n.p.: Slick: Soldier dressed for date.
1947		Jane W. Arnold ‘The Language of Delinquent Boys’ in AS XXII:2 Apr. 122: Slick. A boy who tries to beat the rules of the school. He is seldom caught in his mischief, unless someone tells on him. A slick is usually a smooth talker and sees to it that he has good clothes and the best of everything.
1960		C. Himes Big Gold Dream 97: The slick is a payoff man for the Tia Juana numbers house.
1986		C. Stroud Close Pursuit (1988) 58: Who the hell would replace him? Some slick from State with a Fiberglas suit and the personality of a wolverine.
2002		Scott Phillips Walkaway (2003) 230: A hatchet-faced slick in a houndstooth sportjacket.
2011		J.J. Connolly Viva La Madness 155: Flavio was just the conduit between Slick and the hotel staff.

3. (US, also slick mag) a glossy, expensive, middle-class magazine [SE slick, i.e. high-quality, glossy paper].

1934		Writer Mar. 73/2: Perhaps he [i.e. the author] gets an offer for two hundred dollars from one of the ‘slicks.’ He is enchanted, especially if he lacks experience.
1939		W. Winchell On Broadway 24 June [synd. col.] It makes a racing man titter to read an otherwise good yarn in most of the slick mags when someone gets in a dither [...].
1939		W. Winchell On Broadway 19 Sept. [synd. col.] ‘People’ is the newest of the slicks.
1947		B. Schulberg Harder They Fall (1971) 122: A guy who [...] doesn’t have to go begging for assignments from the slicks.
1964		E. Wilson Earl Wilson’s New York 32: A popular girl-about-New York who’s written for the slick magazines.
2011		H. Ellison Introduction in Pulling a Train’ [ebook] I was working as an editor for [...] the #2 slick men’s mag in the game at that point.

4. a swindler, a hoaxer.

1946		C. Himes ‘The Something in a Colored Man’ in Coll. Stories (1990) 403: Now they were all gabbing [...] the slicks and the squares, the janes and the jills.
1964		R. Abrahams Deep Down In The Jungle 136: Deep down in the jungle, way back in the sticks, / The animals had formed a game called ‘pool.’ The baboon was a slick.
1972		T.M. Kochman ‘The Kinetic Element in Black Idiom’ in Kochman Rappin’ and Stylin’ Out 162: Other operators on the street [...] are known as ‘slicks’ or ‘slicksters,’ by virtue of the ease with which they operate their deceptive maneuvers.
1980		E. Folb Runnin’ Down Some Lines 254: slick, sticker, slickster 1. One who deceives or confounds. 2. One who outwits. 3. One who takes advantage (also a verb).
1999		‘Master Pimp’ Pimp’s Rap 71: Every slick, con man and crook knows she’s still banging that cop.

5. as a term of address.

1955		N. Roberts Honest Illusions 438: ‘Hey, slick.’ ‘Hi.’ Nate studied him for a long moment with a kind of absorbed intensity that made Luke want to squirm.
1977		D. Barthelme Amateurs 75: Hey, slick, came a voice from the parking lot, you gonna fall.
1995		J. Stahl Permanent Midnight ??: ‘Check it out, slick.’.
2000		M. Collins Keepers of Truth 269: I said ‘Okay, slick!’.
2008		K. Shauku Trains 95: Check it out slick, if I wasn’t a hustler, I wouldn’t be in this dive, now would I? I’m trying to make a few bucks.
2019		S.M. Jones Lives Laid Away [ebook] ‘You have to do something for me first, slick’.