Green’s Dictionary of Slang

number one n.

also No. 1

1. oneself, one’s own interests.

T. Pitt in Hedges Diary 23 Feb. (1887) III 99: The Knight I doubt not, but ’tis very careful of number one, and looks no further .
[UK]Sporting Mag. Jan. V 221/1: But don’t go for to think I neglects number one.
[UK]Dickens Pickwick Papers (1999) 701: No man should have more than two attachments — the first, to number one, and the second to the ladies.
[US]J.R. Lowell Biglow Papers (1880) 108: Though, fur ez number one’s consarned, I don’t make no objection.
[UK]Dickens Bleak House (1991) 775: Whenever a person proclaims to you ‘In worldly matters I’m a child’ you consider that that person is only a-crying off from being held accountable, and that you have got that person’s number, and it’s Number One.
[UK]Leaves from Diary of Celebrated Burglar 114/2: Round went the ‘lush,’ Bob still looking out for No. 1, and never letting a glass go by him.
[Aus]Gympie Times (Qld) 7 July 3/1: The others are mere inanities, possessing a keen interest in ‘number one’.
[US]Spectator 22 Mar. 379/1: It is in the early chapters, too, that the author speaks of himself, seldom referring to number one afterwards – for a less egotistical book we have seldom seen [F&H].
[US]Nat. Police Gaz. (NY) 9 Oct. 12: [pic. caption] Two Cyprians, with an Eye to the Interests of No. 1 Take Advantage of a Political Procession to Advertise Their Preferences and Charms.
[UK]Newcastle Courant 25 Nov. 6/5: In his journey through life [he] had kept a close eye upon the interests of No. 1.
[UK] ‘’Arry on His Critics’ in Punch 17 Dec. 280/2: I mean to [...] keep my heye on one mark — Number One!
[Aus]Truth (Sydney) 15 Apr. 4/8: Of course we couldn’t blame him for attending to Number One — every parson christens his own child first.
[UK]W. Pett Ridge Minor Dialogues 159: Ah! you’re all self, James [...] Don’t ’arp too much on number one.
[Aus]‘Dads Wayback’ in Sun. Times (Sydney) 1 June 5/5: Yous wants ter see how they works out fer Number One, as is allus ther cove as wants most looking arter.
[US]A. Berkman Prison Memoirs of an Anarchist (1926) 191: A fellow’s a fool not t’ look out for number one.
[UK]‘Sapper’ Bulldog Drummond 245: Not one in a hundred [...] of the so-called revolutionary leaders in this country are disinterested. They’re out for Number One.
[Ire]Joyce Ulysses 145: Does himself well. No guests. All for number one.
[US]Z.N. Hurston Mules and Men (1995) 66: Ah ain’t puttin’ out not to no ole hard head [...] Ah talks for Number One.
see look after number one
[Aus](con. 1941) E. Lambert Twenty Thousand Thieves 180: Olley tapped his chest and smiled knowingly. ‘The old Number One! I get on with the men but it’s always old Ted, number one!’.
[US]H. Ellison Rockabilly (1963) 153: Who, after all, was looking out for Number One?
[UK]‘P.B. Yuill’ Hazell Plays Solomon (1976) 128: It’s a hard world and your only duty is to number one.
[UK]J. Sullivan ‘Diamonds are for Heather’ Only Fools and Horses [TV script] Like hell he did! Vic looked after number one!
[Aus]B. Ellem Doing Time 93: To survive in here, you’ve got to be hard, you’ve got to be ruthless, you’ve got to look after number one.
[Ire]P. Howard The Joy (2015) [ebook] The time took after number one had arrived — Run, run, ye fucking coward, ye!
[UK]Indep. on Sun. 28 May 21: Gunman who looks after number one.

2. the best, the finest quality.

[UK]Swell’s Night Guide 40: This sanctum-sanctorum is ... the number one of cribberies.
[UK]‘Doss Chiderdoss’ ‘A Clue’ Sporting Times 19 Sept. 1/3: He had nothing but derision for the Scotland Yard division, / They were nowhere, whereas he was number one.
[US]Wash. Post 3 July 3/1: This Victoria hop’s been dribblin’ inter New York [...] at the rate of 50 tins a week. It ain’t quite as good as No. 1 [...] That’s the best in the world.
[Ire]Joyce Ulysses 403: Yours? Mead of our fathers for the Uebermensch. Dittoh. Five number ones.
[US]B. Schulberg On the Waterfront (1964) 144: Johnny was Number One in their book.
[US] letter in Mad mag. Jan. 10: As we say in Korea, it is number one (the best).
[UK]A. Sillitoe Start in Life (1979) 80: You’re number one [...] You might not know it, but you saved my life.
[UK](con. 1940s) J.G. Farrell Singapore Grip 168: ‘Big ah blests number one!’ remarked a smartly dressed young Chinese.
[UK](con. 1950s–60s) in G. Tremlett Little Legs 3: My Dad was number one around here.
[US]‘Master Pimp’ Pimp’s Rap 161: I am number one. I’m Bobby Jones.
[UK]N. Barlay Hooky Gear 53: Well fuckin hell. Number fuckin 1.

3. (orig. US) one’s best friend or lover.

[US]Ade Girl Proposition 69: He was the kind that would take a Friend with him when he went calling on No. 1. He wanted the Friend to see for himself that the Girl thought the World of Papa.
[UK]Sporting Times 1 Apr. 11/2: Each was No. 1 when the other fellow wasn’t there.
E. Shrake But Not For Love 43: [L]ater [i.e. after sex] he said, ‘Janey, you’ve always been the number one’.
[UK]Guardian Guide 10–16 July 93: He’s still number one in Rachel’s affections.
[UK]N. Barlay Crumple Zone 71: I get back from Sabine’s [...] pretty cabbaged, drunk enough for Alv to drive me back the ten-minute walk with his number one, the super-silent Ray, in tow.

4. as juv. euph.

(a) the act of urination.

J. Churchill ‘Seniority’ in Poems II 130: He, coolly, his paper began to prepare / Just adding (for some only mind number... one).
[UK]Farmer & Henley Sl. and Its Analogues.
[US]H. Roth Call It Sleep (1977) 37: ‘You’d better go in and ‘pee’ first [...] How does your mother say it?’ ‘She says numbah one.’.
[UK](con. 1928) R. Westerby Mad in Pursuit 101: An’ you better do Number One before yer leave, too.
S. Beckett Watt (1988) 118: He might have got up, without the bell’s sounding, to do his number one, or number two, in his great big chamber pot.
[US]Baker et al. CUSS 164: Number 1 Urinate.
[US]P. Conroy Great Santini (1977) 54: I gotta go number one real bad.
[Aus]M. Walker How to Kiss a Crocodile 57: When I did try number ones, I strained, grunted and groaned as I hovered over the porcelain bowl. Not even a drop.
[US]W.T. Vollmann Royal Family 448: Oh, my darned dog won’t poop. He’s done number one, but he just won’t do number two.
Guardian Festivals 21 May 5/2: You only need the toilets for number twos. Number ones can be done anywhere.
[UK]J. Meades Empty Wigs (t/s) 828: He verbally abused visitors coming back from the toilet. He would be asking them if they’d done a number one or a number two.

(b) urine.

[Aus]B. Humphries Barry McKenzie [comic strip] in Complete Barry McKenzie (1988) 60: Brit beer tastes so like No. 1 we probably wouldn’t know the difference.
[US]J. Lahr Hot to Trot 166: We call it ‘tinkle’ or ‘number one’.
[UK]A. Higgins Donkey’s Years 30: Coffey [...] lets No. 1 go between his legs. It splatters on the drain.

(c) a chamberpot.

[UK]Farmer & Henley Sl. and Its Analogues.

5. an extremely short ‘skinhead’ hair-style [from the setting of the hair-clippers at ‘1’].

[US](con. c.1967) J. Ferrandino Firefight 30: ‘You want number-one hakkut, Joe?’ the barber asked.
[US]T. Jones Pugilist at Rest 83: He told me I could not leave the base until I got a No. 1 haircut.
[UK]Indep. on Sun. Culture 11 July 2: You’ll see a chunky bloke with a No 1 crop.
[UK]Guardian Space 13 Apr. 18: Then another of those blokes appeared – No 1 crop, Crombie, pit bull on a string.
[Scot]T. Black Ringer [ebook] n.p.: Dungarees is the slippery slope. Next is the Doc Martens and the Number 1 to the napper.

6. (UK prison, the punishment diet of bread and water; N.Z. prison) a severely limited diet.

[UK]J. Curtis Gilt Kid 65: Serve him right if he had to go without any grub for a few days same as a bloke might get three days’ No. 1 back in stir.
[Ire]B. Behan ‘I Became a Borstal Boy’ in After the Wake (1981) 26: I would have been reported to the Governor [...] and have got No. 1 (bread and water) ‘to cool me off’.
[NZ]I. Hamilton Till Human Voices Wake Us 106: They’d feed him No. 1 ration for a while.
[Ire]J. Phelan Tramp at Anchor 180: Uh-huh — three number one.
[UK]‘Charles Raven’ Und. Nights 141: He was given three days’ No. 1 diet and fourteen days’ No. 2.
T.R. Shadbolt Bullshit and Jelly Beans 11: Once some guys tried to organise a petition about the food - they were put into "the digger" on Diet Number One: 80z. potato, 40z. fat, five slices bread, Y2 pint milk.
G. Newbold Punishment and Politics 126: 1961 saw the abolition of bread and water punishment and its replacement with two grades of restricted diet ... the more extreme of these, no. 1 diet, provided for a daily regimen of bread, potatoes, milk and dripping.
[NZ]A. Duff One Night Out Stealing 43: Number one was cold potatoes, glass of milk, piece of bread for three meals a day three days on end.
[NZ]D. Looser Boobslang [U. Canterbury D.Phil. thesis] 126/1: number one n. 1(also number one dietor number one ration) Restricted Diet Number One (abolished by the Bill of Rights on 1 April 1981).

7. (US Und.) first degree (i.e. pre-meditated) murder.

[US]E. Folb Runnin’ Down Some Lines 24: I’m on parole for number one.

8. (NZ prison) a prison bully, an inmate who attempts to run a prison wing.

[NZ]D. Looser ‘Boob Jargon’ in NZEJ 13 33: number one n. Bully, controller; intimidating person who tries to run the wing.

In phrases

look after number one (v.) (also look out for..., mind..., take care of...)

to take care of oneself, irrespective of others.

[UK]Vulgarities of Speech Corrected n.p.: To mind number one [...] To be attentive to interest.
[US]Whip & Satirist of NY & Brooklyn (NY) 22 Oct. n.p.: She will always take care of No. one.
[Ire]E.L. Sloan ‘Mrs. Sleek’ in Bard’s Offering 71: Mrs. Sleek slimmed the cream for her butter— / Well she knew how to mind number one.
[US]G. Thompson Gay Girls of N.Y. 88: I’m a poor lone widow and I must take care of number one!
[UK]Sheffield Indep. 23 Dec. 15/1: Mother Mahomney was supposed to be a widow, and if so so, a widow better able to look after No 1 I don’t care at all to see.
[UK]Era (London) 7July 16/1: Acute brokers devote their energies to taking special care of No. 1, and rarely come out ‘at the small end of the horn’.
[UK]W. Pett Ridge Mord Em’ly 261: I’m going to look after Number One, an occupation I ’ave pre’aps ’itherto neglected.
[US]W.R. Burnett Dark Hazard (1934) 25: Look after number one, in this case, your job.
[US](con. 1920s) Dos Passos Big Money in USA (1966) 908: There are darn few who won’t look out for number one first.
[US]N. Algren Never Come Morning (1988) 46: I believe I got to take care of number one then.
[US]‘John Eagle’ Hoodlums (2021) 50: The only certain thing about Marty was his ability to take care of Number One.
[UK]N. Barlay Curvy Lovebox 169: You must [...] take care of numbah one.
[Ire]P. Howard PS, I Scored the Bridesmaids 35: I’m doing what you do, Ross. I’m looking after number one.