Green’s Dictionary of Slang

1. to urinate.

c.1597		Shakespeare Henry IV Pt 1 II i: Why, they will allow us ne’er a jordan, and then we leak in the chimney.
1611		Rowlands ‘Master Make Shift’ Knave of Clubs 19: Then sing me, I could fancie lovely Nanny, (And here is for you, I’le but goe and leake; Call for a pot, ther’s not a rogue will speake.) So takes his cloake, and downe the staires away.
1731		Swift ‘Strephon and Chloe’ Miscellanies V (1736) 37: Twelve Cups of Tea [...] Has now constrain’d the Nymph to leak.
c.1786		Grose Classical Dict. of the Vulgar Tongue ms. additions n.p.: To Leak, to Make Water.
1788, 1796		Grose Classical Dict. of the Vulgar Tongue (2nd, 3rd edn).
c.1800		‘Peter Pindar’ ‘Royal Visit to Exeter’ Works (1801) V 107: The King no notice tuke, ’tis zaid, But, leek a pisky, laugh’d and play’d To push-pin wey the Queen.
1811		Lex. Balatronicum.
1823		Egan Grose’s Classical Dict. of the Vulgar Tongue.
1846		Swell’s Night Guide 73: Times are badly changed since John the hostler lived here; then every bed had a jordan; but now you must leak in a chimney corner.
1932		‘R. Scully’ Scarlet Pansy 258: A real he-man can always leak without turning on the water faucet.
1944		A. Kapelner Lonely Boy Blues (1965) 92: I wouldn’t leak on your grave!
1957		Kerouac On The Road (1972) 87: The prowl car came by and the cop got out to leak.
1965		S. Selvon Housing Lark 125: ‘I feel to piss.’ ‘Go and find a tree. I just leak against a oak over there.’.
1973		(con. 1940s–60s) ‘Cats on the Rooftops’ in Hogbotel & ffuckes Snatches and Lays 26: The poor old desert camel has no water for a week, / And as he doesn’t drink, the poor bugger cannot leak.

2. to reveal a secret unintentionally, or intentionally [now SE].

1859		Matsell Vocabulum.
1878		Nat. Police Gaz. (NY) 18 May 6/4: The favored few [...] swore eternal secrecy, but [...] have ‘leaked’ in some manner.
1887		‘’Arry in the Witness-Box’ Punch 5 Feb. 61/2: The plaintiff [...] seemed to go slap orf ’is chump / And leaked orkurd facts like a sieve when the Counsel jest put on the pump.
1894		Worthington Advance (MN) 31 May 6/2: ‘Roping’ means to work into the confidence of man under suspicion [...] and become so friendly that he will ‘leak’ what you are after.
1895		C. Crowe Aus. Sl. Dict. 44: Leak, to impart a secret.
1907		W.M. Raine Bucky O’Connor (1910) 114: Somebody’s leaked, or else he has a spy in our councils.
1933		Ersine Und. and Prison Sl.
1935		R. Chandler ‘Spanish Blood’ Spanish Blood (1946) 12: Leak this to your favorite newshawk and you’re out a job.
1953		R. Chandler Long Good-Bye 286: Personally I don’t figure it was Lawford who leaked. He’s a politician too.
1974		‘P.B. Yuill’ Hazell Plays Solomon (1976) 90: This big builder thinks one of his staff is leaking.
1982		P. Theroux London Embassy 192: I was asked to leak it to the British press.
1990		(con. early 1950s) J. Ellroy L.A. Confidential 231: You leaked word to him on Mr. McPherson’s quote dark desires.
2000		Indep. 15 Jan. 7: Hunt widens for ‘mole’ who leaked fake nuclear data.

3. (US) to lie.

1909

(ref. to 1880) in J. Ware Passing Eng. of the Victorian Era.

4. (US, also turn on the leaks) to weep.

1883		G.W. Peck Peck’s Bad Boy and His Pa (1887) 44: When his eyes began to leak, Pa put his hand in his tail-pocket for his handker, and got it out.
1896		Ade Artie (1963) 57: She claimed it was the happiest day of her life, and then as soon as she said it she commenced to leak again.
1933		C. Himes ‘Prison Mass’ in Coll. Stories 164: Then she had turned on the ‘leaks’—just a pitiful little victim of a big, bad, stick-up man.
1995		J. Cameron Vinnie Got Blown Away 126: Monday blubbed before we went to school, blubbed dinnertime we came back then still leaking after school.
2002		J. Cameron Hell on Hoe Street 197: Now she was leaking and shaking like she was gutted.
2012		R. Milward Kimberly’s Capital Punishment (2023) 423: I’m dripping my own tears onto her cheeks. Shaun never likes me leaking on the corpses.

5. (US) to rain.

1905

J.W. Carr ‘Words from Northwest Arkansas’ in DN III:i 86: leak, v. To rain. ‘Take an umbrella, it looks like it’s going to leak’.

6. (US) to bleed.

1986		C. Hiaasen Tourist Season (1987) 227: The sonofabitch leaked pretty good. He’s got to be hurting.
1998		Big L ‘Ebonics’ 🎵 Smilin’ is cheesin’, bleedin’ is leakin’.