Green’s Dictionary of Slang

1. the nose [? beak n.² (1) and/or coconut n.¹ (1); Ware suggests an alternative ety., the clown Joseph Grimaldi’s (1779–1837) trademark tapping of his nose with the comment, C’est beaucoup, that’s plenty].

1859		Matsell Vocabulum 125: boko. The nose.
1860		Sporting Life (London) 17 Oct. 3/4: Some sharp infighting took place, Tyler on the side of the nut, drawing the claret, and on the boko.
1865		Leaves from Diary of Celebrated Burglar 63/1: Tommy Davis, alias Cankey, alias Boko, a fellow with a tremendous ‘smeller,’ whereby he got his cognomen.
1879		Besant & Rice ‘The Seamy Side’ in Appleton’s Journal (N.Y.) May 447: A common-keeper [...] got a heavy oner on the boko for his share.
1886		Sporting Times 30 Jan. 6/1: The second [boot] hit the dear old lady [...] on the boko.
1889		Dead Bird (Sydney) 21 Sept. 5/1: They Say [...] A mill between Griffo and ‘Boko’ Thomspon [...] would be a big attraction.
1890		Sporting Times 15 Feb. 1/5: Portugal made a small fool of itself, and has been squelched, and anyone else who takes a liberty will get a similar punch on the boko.
1894		Truth (Sydney) 18 Mar. 2/6: The lady cavalier immediately landed the jocular gent ‘a beauty of the boko’.
1895		T.W. Connor [perf. Little Tich] ‘All Over the Shop’ 🎵 Got a whopper on the ‘boke’ — couldn't see the other bloke.
1895		N. Melbourne Gaz. : They Say [...] That Peter McMaster shoved Polglase on his ‘boco’ in the citizen’s race.
1897		W.S. Maugham Liza of Lambeth (1966) 108: Give ’er one on the boko.
1900		‘Doss Chiderdoss’ ‘The Babel Stakes’ Sporting Times 26 May 1/4: A jockey now takes his partic’lar seat where’er there’s a vacant spot. / For some of ’em cling round the horse’s neck, or over his ‘boko’ bend.
1901		W.A. Sun. Times (Perth) 15 Dec. 1/1: He of the rubicund boko some nothing of the daylight till the tawny tipple had vanished.
1906		Marvel 13 Oct. 335: Bet you [...] that I could catch old Homer on the boko!
1906		Sun. Times (Perth) 11 Nov. 4/7: Battered his boko, bunged his lip.
1908		Magnet 15 Feb. 3: Then here goes for your boko!
1914		W.L. George Making of an Englishman III 299: ‘Fetched him one on the koboko,’ Maud summed up.
1915		C.J. Dennis ‘The Stoush O’ Day’ in Songs of a Sentimental Bloke 29: ’E shoves ’is boko o’er an Eastern ’ill, / Then rises, wiv ’is dial all a’ grin.
1918		Dagger [London] Dec. I 4/1: I tipped him on the boko with a brick bat.
1924		(con. WWI) A.G. Pretty Gloss. Of Sl. [...] in the A.I.F. 1921–1924 (rev. t/s) n.p.: boko. Nose.
c.1939		B. Bennett ‘Sobstuff Sister’ in Billy Bennett’s Third Budget 18: Each week she was in a schemozzle, / Either biting the ears off Clark Gable, / Or biting the boko off Schnozzle.
1944		J. Cary Horse’s Mouth (1948) 32: Hit her with something harder. On the nose. Toko on the Boko.
1959		I. & P. Opie Lore and Lang. of Schoolchildren (1977) 216: Biff him on the boko.
1961		‘Frank Richards’ Billy Bunter at Butlins 110: ‘Oh! Ow! My boko! Wow!’ His hand went to his nose.
2003		Brummagem Dict. 🌐 The smoke from that chimbley in Montague Street’s got a snatch as sticks in yer boko.
2012		D. O’Donnell Locked Ward (2013) 248: It struck me flush on the boko, and I squealed.

2. a person.

1885

‘’Arry on Song and Sentiment’ in Punch 14 Nov. 229/1: The bokos who try other barneys are bossing about in the dark.