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.
[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!
[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.
[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.

(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.
[US]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.

[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’.
[UK]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.
[NZ]G. Newbold Big Huey 251: number one (n) Restricted diet No. 1 (abolished).

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.

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.
[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.
[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.