Green’s Dictionary of Slang

1. (US teen) of a person, unmotivated or lazy.

1875		Taunton Courier 3 Nov. 7/2: A loafing, slack, lazy fellow who wouldn’t do anything.
1885		Bulletin (Sydney) 4 Apr. 12/1: ‘The hand of Providence is clearly shown in this Soudan business,’ said the ‘slack’ limb-maker, as he ordered in an extra thousand feet of timber, and started to cut out wooden legs.
1886		Sherman Co. Dark Horse (Eustis, KS) 30 Sept. 4/7: The owner was too slack and lazy to dig.
1899		Kipling ‘An Unsavoury Interlude’ Complete Stalky & Co. (1987) 88: Your house is so beastly slack, though.
1904		Nottingham Eve. Post 19 Mar. 4/3: [P]risoner had got into slack, lazy habits.
1907		Morn, Post (London) 29 Aug. 3/3: The workmen [...] for want of stern supervision, have grown slack and lazy.
1912		Stage (London) 23 May 17/5: He was a slack, lazy, lackadaisical creature.
1921		Exeter & Plymouh Gaz. 11 Oct. 3/2: If you are careless, slack, lazy, wilfully slow at your work [...] it cannot be pleasing to God.
1932		St Clair chron. (MO) 21 Apr. 7/5: They weren’t quite so wild going home — sort of slack and lazy.
1941		Jrnl & Courier (Lafayette, IN) 3 Mar. 6/3: Slack women, lazy women, self-indulgent women sigh and say that you can’t tell how children are going to turn out.
1947		K. Amis letter 14 Apr. in Leader (2000) 129: Jesus Murphy, Phil, what goes on at your end? Not as if it’s the first time, you slack shit.
1951		Londonderry Sentinel 27 Jan. 4/7: We are too slack and lazy to resist, and so prepare the way for totalitarianism.
1966		T. T. Keyes All Night Stand 34: If the other lot had come, I wouldn’t have had you slack lot in here.
1977		Eble Campus Sl. Apr. 4: slack – lazy, negligent of one’s responsibilities.
1981		A. Weller Day of the Dog 134: He doesn’t care if it is Jamie, who has lapsed into his brusque mood and who will tell him off for being slack. He is just so buggered.
1997		J. Birmingham Tasmanian Babes Fiasco (1998) 217: I’m going to make it my mission in life to acquire the place you’re living in you slack moll.
2001		K. Sampson Outlaws (ms.) 8: Them boys was the slackest cunts you ever saw.
2014		me-stepmums-too-fuckin-hot-mate at www.fakku.net 🌐 Brekkie’s up, you slack cunt.

2. of individuals or inanimate objects, e.g. a job of work, unsatisfactory or substandard.

1956		S. Selvon Lonely Londoners 95: He couldn’t palm off no slack work on the old Galahad at all.
1987		Eble Campus Sl. Spring 7: slack – unkind, not thoughtful, wrong.
1988		‘Kylie Mole’ (Maryanne Fahey) My Diary 44: She said it was a pretty slack birthday, and they were only allowed to go on two rides each.
1989		B. Bryson Lost Continent 243: [I]f the townspeople ever tried anything slack with the streets he’d have been onto them right away.
1998		R. Frankland Across Country 72: I get a little scared and cause I think I feel spirits close by I quickly (in a real slack attempt at being cool and casual), get back in the car, start up and churn up gravel as I drive off.
2003		McGill Reed Dict. of N.Z. Sl. 191: slack Anything a teenager does not care for.
2007		L. Redhead Cherry Pie [ebook] ‘Listen, you slack moll’.

3. (Aus./W.I./UK black) sexually available, promiscuous.

1979		Lette & Carey Puberty Blues 46: Girls never talked to each other about screwing. If you did you were slack.
1981		A. Weller Day of the Dog 140: [He] studies her lascivious body as he has watched Silver and Pretty Boy do to many a slack girl.
1990		L. Goodison Baby Mother and King of Swords 68: This is how Golden Days became the slackest singer in Jamaica.
1990		T. Winton Human Torpedo 122: You think I’m slack, don’t you?
2003		Skinnyman intro. on Itch-FM Lost City [CD] That’s why I stay slack, that’s why I stay vulgar.
2011		S. Kelman Pigeon English 70: If a girl has an earring in her tongue it means she’s slack.

4. lewd, vulgar, used of dancehall reggae lyrics .

1987		D. Hebdige Cut ’n’ Mix 125: The new Jamaican djs like Ringo and Lone Ranger soon followed Yellowman with copycat ‘slack’ tracks.
1995		G. Small Ruthless 190: The undisputed king of dancehall was Yellowman, a black albino with a unique line in ‘slack’ lyrics.

5. (US campus) easy.

1982

Eble Campus Sl. Spring 7: slack – easy or unchallenging [...] English is a slack major.

6. (US teen) amicable, friendly.

1981

Detroit Free Press (MI) 6 July 17/1: slack (I’ll be your slack) — on your side.