Green’s Dictionary of Slang

(a) tipsy, slightly drunk.

1802		Naval Chron. VII 273: The Amelia’s men being a little on, could not bear being thwarted, and a violent scuflle ensued .
1864		Derby Day 119: She’ll be ‘on’, sir, as sure as eggs is eggs.
1866		Night Side of N.Y. 52: Now and then there sallies forth from a drinking-salloon some belated market-gardener from New Jersey, who has got ‘pretty well on’.
1874		Leeds Times 28 Mar. 6/5: He is bloomin’ well brewered, there’s no kid. He was on, s’help me tatur!
1885		Bulletin (Sydney) 17 Jan. 12/3: How to get ‘on’: Drink a quart of colonial beer.
1885		‘’Arry on the Merry Month of May’ in Punch 16 May 229/1: Returning at dusk with the beer on.
1886		Nat. Police Gaz. (NY) 6 Feb. 6/3: Some woman, taking advantage of her masque, would accost some male individual and ask him [...] ‘was he on’.
1895		W. Pett Ridge Minor Dialogues 288: He’s a bit too handy with his walking-stick, though, sometimes, when he’s a trifle on.
1899–1900		H. Lawson ‘The Chinaman’s Ghost’ in Roderick (1972) 351: We nearly always wanted to fight each other when we got a bit on.
1900		G.R. Sims In London’s Heart 85: You said he was always a bit on, Dook [...] he ought to be easy enough to tackle if that’s right.
1905		L.C. Cornford Canker at the Heart 9: Mind when I cleared out the boss and the ganger-man that night, old mate, me being a bit on?
1916		N. Douglas London Street Games 154: He was a bit on, that night, was Mr. Perkins.
1926		Breton & Bevir Adventures of Mrs. May 21: There’s no good argyfyin’ with a gentleman, ’speshly when ’e’s a bit on.
1936		(con. 1830s–60s) ‘Miles Franklin’ All That Swagger 139: We might have been a little on, not being used to liquor.
1981		J. Ellroy Brown’s Requiem 28: [I]n his perpetual T-Bird haze he can transform his wino fantasies into insights [...] , for I was exhilarated myself, and felt the need of his stimulus.
1992		I. Rankin Strip Jack 233: I was well on by then, mind.

(b) in a general sense, using a particular drug regularly, addicted to a drug; note, where the drug is specified see on prep. (9a)

1938		D. Maurer ‘Lang. of the Und. Narcotic Addict’ Pt 2 in Lang. Und. (1981) 106/2: To Be on. Var. of To Be on drugs. To be addicted and actively indulging the habit.
1953		‘William Lee’ Junkie (1966) 121: It took me just three days to get back on.
1967		P. Thomas Down These Mean Streets (1970) 115: ‘I wish I had me some stuff.’ ‘You on, man?’ ‘Yeah, you?’.
1978		R.D. Pharr Giveadamn Brown (1997) 88: ‘Did you tell Harry you were once on the stuff?’.

(c) intoxicated on a drug of any kind.

1952		(con. 1948) G. Mandel Flee the Angry Strangers 247: If hashish don’ put you on, lady, like-you better stick to lusho.
1958		H. Ellison Web of the City (1983) 162: The kids were on. They were real high. Sky.
1959		W. Burroughs Naked Lunch (1968) 254: Meet a girl in the hall and I see she is on and ask where is a score?
1961		T. Taylor Baron’s Court All Change (2011) 153: ‘Get on this [spliff] man, it’ll do you the world of good’.
1980		(con. 1940s–60s) H. Huncke ‘Alvarez’ in Eve. Sun Turned Crimson (1980) in Huncke Reader (1998) 186: It wasn’t difficult to see she was obviously on, and I said, ‘Baby, you look straight.’.
1997		Simon & Burns Corner (1998) 77: And then, at last, she’s in and they’re on, the pinkish cloud rising into the syringe as bottom-line proof.

(a) involved in a wager; thus get on v., to place a bet; you’re on phr., your bet has been taken.

1812		Sporting Mag. XXXIX. 23: They declared themselves off, a thing unknown in sporting, after they had been on [OED].
1828		‘A Flat Enlightened’ Life in the West I 45: [H]is lordship instanter would have declared himself ‘on,’ (in sporting parlance).
1836		Spirit of the Times (N.Y.) 5 Mar. 20/1: Other parties were anxious to ‘get on’ at this price, but could not succeed.
1854		G.J. Whyte-Melville General Bounce (1891) 190: ‘Come Bracketts, spring a point, and I’ll put you ‘on’ about ‘Sennacherib’ for the Goodwood Cup.’.
1854		N.Y. Clipper 14 Jan. 3/3: [I]f the plaintiff [...] should [...] endeavor to ‘get on’ a ‘good thing,’ he will receive the ‘cold shoulder’.
1855		(con. 1839) Fights for the Championship 149: Many who lamented the impossibility of ‘getting on’ before the fight have now [...] the consolation of feeling that they have ‘got off’ lightly.
1864, 1867, 1870		Hotten Sl. Dict. 191: On ‘I’m on’ also expresses a person’s acceptance of an offered bet. To get on a horse or a man is to make bets on it or him.
1868		Pall Mall Gaz. 15 May 12/1: A race of budding swindlers [...] classed with Mr Charlton who plays ‘dark’ at billiards in the hope of getting some money ‘on’ before contending for the cue.
1871		Sporting Gaz. (London) 11 Feb. 11/3: And those who are ‘on,’ resting calm in their strength, / Think to silence all other ‘great guns’.
1881		W. Black Beautiful Wretch III 27: I’ll bet you five sovereigns to one that they let him out on the next application [...] Are you on?
1885		Bulletin (Sydney) 14 Feb. 6/2: We’ve had, we own, a splendid grin / O’er your most fearful, hard-earned win; / But our smiles fade, Canadian son – How can we get our money on?
1890		Sporting Times 29 Mar. 2/5: M stands for the ‘Master,’ the far famed ‘John,’ / Whose gee-gees—thank goodness—I never am ‘on’.
1899–1900		C.L. Cullen Tales of the Ex-Tanks 152: ‘I’ll bet you a hunded the king wins,’ said I. [...] ‘You’re on,’ said the dealer.
1900		Bulletin (Sydney) 27 Oct. 24/1: Sydney shop-totes swindle was never more glaring than on Saturday. [...] Once in a way big divs. are heard of, but ’tis any odds that the manipulator himself is the only one then ‘on.’.
1907		C.E. Mulford Bar-20 iii: ‘Yore on,’ promptly responded Hopalong, who would bet on anything.
1907		D. Stewart Shadows of the Night in Illus. Police News 10 Aug. 12/4: ‘What’s the odds! I’m on!’.
1914		Chillicothe (MO) Constitution 9 Jan. 3/1: ‘You’re on,’ he said strongly.
1915		Drew & Evans Grifter 115: ‘A man could get “on” easy enough if we had the Tote’.
1916		R. Lardner ‘Champion’ in Coll. Short Stories (1941) 113: ‘I’m offerin’ you this Tracy bout. Take it or leave it.’ ‘All right; I’m on,’ said Midge.
1926		‘Sapper’ Final Count 814: If yer gets on now yer gets on at 66 to 1.
1936		R. Chandler ‘Guns At Cyrano’s’ in Red Wind (1946) 205: You’re on, sucker.
1949		L. Glassop Lucky Palmer 3: He was forced to listen to the face without being able to get his two shillings on.
1957		‘Nino Culotta’ They’re a Weird Mob (1958) 151: ‘Bet y’ another dollar ’e’s got a rabbit.’ ‘Yer on, mate.’.
1960		(con. 1940s) D. MacCuish Do Not Go Gentle (1962) 235: ‘Make it five!’ ‘You’re on!’ They shook hands.
1982		J. Sullivan ‘A Losing Streak’ Only Fools and Horses [TV script] You’re on!
1992		K. Lette Llama Parlour 23: ‘You won’t survive LA, I betcha.’ [...] ‘You’re on,’ I said. ‘One hundred bucks.’.
2000		C. Osgood See You on the Radio 103: You say, ‘I bet you a dollar.’ He says, ‘You’re on.’.
2008		W.M. Raine Steve Yeager 116: ‘Bet you a box of chocolates against a ham sandwich I can.’ ‘You’re on,’ she nodded airily.
2011		J.J. Connolly Viva La Madness 212: We having a flutter, or what? [...] We on or what?

(b) (orig. US) in favour of, or willing to take part in something, ready to do something, e.g. I’m on, I agree with that.

1872		‘Mark Twain’ Roughing It (2007) 143: Pard, he was on it! [...] On the fight, you understand.
1876		C. Hindley Life and Adventures of a Cheap Jack 6: All right, Governor – we are on! and thank you too.
1887		‘’Arry on Angling’ in Punch 30 July 45/1: The ’ole thing seemed swell with good grubbing and lots o’ prime lotion chucked in. I was ‘on’ like a shot.
1894		Truth (Sydney) 11 Feb. 7/2: But we weren’t fit for bullocking, and said we were not on.
1899		C. Rook Hooligan Nights 134: I was on for a bit of a game.
1903		A. Binstead Pitcher in Paradise 14: If you’ve nothing better to do I can offer you a little entertainment with the E Division of Police [...] Are you on?
1911		G. Bronson-Howard Enemy to Society 343: Your salary would be a hanged sight more than you ever earned. Are you on?
1919		‘Bartimeus’ ‘Narrative of Commander W.D. Hornby’ in Awfully Big Adventure 79: ‘A Captain is wanted to command a certain unit of the force; are you on for it?’ ‘I’m on for it all right,’ I replied.
1929		W.R. Burnett Little Caesar (1932) 18: ‘The boy’s on?’ ‘All set.’.
1934		B. Appel Brain Guy (1937) 137: ‘We’re stepping up to the Bronx. You on?’ ‘Sure I am.’.
1936		J. Curtis Gilt Kid 123: Put me out of my agony. Give me the strength of it. You know I’m on now.
1943		R. Llewellyn None But the Lonely Heart 171: ‘Just come in and put them in my hand. I can do with them.’ ‘That’s on,’ he says.
1951		D. Stivens Jimmy Brockett 235: I had an idea of making a night of it and Jerry said he was on.
1966		T. Keyes All Night Stand 15: I smiled at her. Yes it was on. Now I ignored her.
1976		P. Theroux Family Arsenal 247: ‘I’m on,’ said Lady Arrow.
1986		F. Taylor Auf Wiedersehen Pet Two 252: Bomber’s on!
1998		I. Welsh Filth 143: I bell Bladesey to tell him we’re on.
2000		G. Pelecanos Shame the Devil 151: We on this weekend, Dimitri? [...] Gonna be a little cold down there on the property, but the weather should be clear.

(a) (US) fully comprehending or well aware of.

1865		Leaves from Diary of Celebrated Burglar 6/1: We were all assembled over our ‘lush’ [...] when the ‘office’ was given that the ‘coppers’ were ‘on’.
1885		Santa Fe Weekly New Mexican 9 July 2/2: He hoped to sell the cavalry a large lot of supplies, but Major Van Horn was ‘on’ [DA].
1899		Ade Fables in Sl. (1902) 68: The Preacher didn’t know what all This meant, and he didn’t care, but you can rest easy the Pew-Holders were On in a minute.
1902		E. Townsend Chimmie Fadden and Mr Paul 17: You ’re on dat Duchess is Miss Fannie’s maid.
1904		C. Connors Bowery Life [ebook] It's a hundred ter one shot dat erbout half uv de stuff he had ter leave behind is goin’ ter buy wine [...] fer a bunch uv stage Tommies. Are yer on?
1918		D.G. Rowse Doughboy Dope 17: The boys don’t mind him, and he figures that folks on the outside are not on.
1929		M. Levin Reporter 343: The dope today is that the boys are on.
1931		Irwin Amer. Tramp and Und. Sl. 137: On.–Wise ; experienced ; aware of the facts.
c.1951		N. Algren ‘Watch Out for Daddy’ in Entrapment (2009) 118: ‘It [i.e. a heroin injection] was into the vein and the first was just into the skin.’ I let him know I was on.
1952		‘Josephine Tey’ Singing Sands 76: He had been ‘on’ in the affair from first to last [...] As a source of information he was pure horse’s mouth.
1956		N. Algren Walk on the Wild Side 71: You can stop putting on the weakminded act for me any time now [...] I’m on.
1987		(con. 1967) E. Spencer Welcome to Vietnam (1989) 57: Even when I’m not getting hit, I’m on.

(b) (later use US black) sophisticated, informed, at an advantage, fashionable.

1887		I.M. Rittenhouse Maud (1939) 403: He looked so good to my eyes standing there in his dark suit, [...] even the tie I preferred—a small dark one instead of the big flashy things that are ‘on’ now.
1959		Mad mag. Sept. 41: It’s for us, the on-cats, who ought to pick up on those still-wailing blues.
1970		Time 10 Nov. 42: Dylan is the outsider. He’s the most on person in America.
1980		Eble Campus Sl. Spring 4: on – in vogue: That disco is really on.
2002		‘Touré’ Portable Promised Land (ms.) 157: We Words (My Favorite Things) [...] Nuff said. Don’t sleep. It’s on! I’m down. I’m ghost. I’ma jet.

(c) (US) good, positive [as opposed to off adv.¹ (4)].

1889		World (N.Y.) 1 Aug. 10/5: Staley had an ‘on’ day and was very effective.
1942		A. Christie Body in the Library (1959) 128: I see him in his ‘off’ moments, not only in his ‘on’ ones.

(d) (Aus.) alert, keeping one’s eye on someone.

1960		‘Nino Culotta’ Cop This Lot 41: Be on ’im. [...] Dobbin’ us in.
1988		A. Payne ‘The Last Video Show’ in Minder [TV script] 27: I want someone on him every second.