Green’s Dictionary of Slang

1. anything of excellent quality; an outstanding person (irrespective of gender) or thing.

1905		Bulletin (Sydney) 26 Oct. 24/2: Only one century appeared, and that was what the classic Greek poet Pindar called a ‘bonzerina,’ A.B.S. White, of North Sydney, carrying his bat out for 198.
1906		Bulletin (Sydney) 20 Dec. 15/3: I think he is wrong in giving ‘bonzarina’ as the feminine of that classic word. I have always heard the latter used as denoting the ne plus ultra of bonzarosity, without distinction of sex. The tendency at present, however, is towards condensation rather than elaboration, and the up-to-date weary slang-whanger briefly remarks: ‘Ain’t it a bon?’.
1907		Peak Hill Exp. (NSW) 1 Nov. 9/1: Mother seized the axe (she is a bonserina with the axe), and the blade descended with unerring accuracy.
1907		Brisbane Courier 29 May 6/3: As against the ‘boshter bloke’ we find the ‘yob,’ or clumsy fellow; the ‘nark,’ or spoil-sport; the ‘rotter,’ with whom we are bade to ‘have no truck’; and the ‘mug’ or duffer. These may not be named in the same breath with the ‘bonzalina’ footballer. […] ‘Hiawatha’ might have been described with equal accuracy as a ‘bonzer,’ a ‘bonzalina,’ or a ‘bontoshter.’.
1909		Bulletin (Sydney) 13 May 26/1: In the words of the barracker, Saturday’s match was a real blanky bonzerina – a boshter of the most bonzer type.
1910		Eve. News (Sydney) 25 Mar. 7/3: ‘Bosker,’‘bontoshter,’‘bonzarina,’ were among the words that were applied to the giant growths, and not a few of the adults looking on smiled approvingly.
1911		Golden Gate (Fremantle) 26 Aug. 2/2: Just tell Sharpe Senior that his son is a bonzarina, a slap-up, dyed-in-the-wool football genius.
1934		Nthn. Standard (Darwin) 3 July 7/3: The one I spoke of last week is a bonza – or bonzarina. It’s hind part was as big and round as a 1lb. perfectly round tomato, 3½ inches in length, 2 inches in width, and between two and three inches in height.

2. (Aus.) a notably beautiful woman; thus used as adj.

1906		Bulletin (Sydney) 22 Nov. 17/2: This is a bonza, a sort of improvement on the boshter, and bonzarina, feminine of bonza.
1906		Sun. Times (Perth) 24 June 4/8: Twenty thousand dashing damsels from the land of beef and beer [...] It’s a bonzarina bonus [...] ‘Send ’Em Out’!
1909		Sun (Kalgoorlie) 10 Jan. 9/1: The ‘little bonzerinas’ are evidently enjoying themselves, and receive many a cheer as they flaunt gaily along the street.
1910		Bulletin (Sydney) 28 Apr. 10/2: What makes me weariest in well-doing is the name the Bonser or the Bonserina is saddled with –‘Clyfford Napoleon De laval Cambridge,’ or ‘Inez Clytie Imogene Talleyrand,’ or some thing equally variegated.
1911		Labor Call (Melbourne) 27 Apr. 2/1: At the Theatre Royal: ‘The Belle of Brittany’; Now, when is somebody going to write a really up-to-date musical comedy and call it ‘The Bonzerina of Australia’?
1912		Sun (Kalgoorlie) 25 Feb. 5/5: [H]e dug me in the ribs. ‘Ain’t she a bonzarina? Ain’t she Sir Garneo? Ain’t she a credit to the town?’.
1934		T. Wood Cobbers 212: She was a little bonzarina.
1950		F.J. Hardy Power without Glory 45: She’s a bonzarina shiela, like a colleen from old Ireland. She’ll make a cosy little bedmate for some lucky bloke one of these days.
1951		D. Stivens Jimmy Brockett 141: I got her undressed. She was bonzerina, as we used to say [...] I’d never seen such a white skin on a sheila.
1961		T. Wood Cobbers 212: And the girls who took you rowing on the Serpentine! My word! I was in the Strand one time, and a cobber o’ mine introduced me. She was a little bonzarina.