Green’s Dictionary of Slang

1. a good thing; an excellent example.

1901		Lyttleton Times 20 Apr. 1: [advert] ‘bonzer’ In the vernacular means excellent: our remingtons Are ‘Bonzers’.
1903		Herald (Melbourne) 20 Feb. 2/5: He made a brilliant run for a catch, and was successful in closing the Baptists’ innings with a ‘bonza’ of a ball.
1904		Bulletin (Sydney) 14 Apr. 29/1: Re that bulwark of Austral Slanguage — ‘Bonster’. .. A bonser or bonster is comparatively superior to a bons.
1904		Australasian (Melbourne) 9 Jan. 44/1: [A]s I went away I said, ‘Having a good time to-day, old man?’‘My oath, miss! it’s a ‘bonza,’ he said.
1905		Coolgardie Miner (WA) 23 Feb. 1/4: [advert] =SUMMER SALE= WHICH IS NOW BOOMING. Do Not Miss it! It is a Bonzah!
1906		E. Dyson Fact’ry ’Ands 82: I know sev’ral chronics what’s cultervated it, but mine’s ther bonzer.
1906		Greymouth Eve. Star 15 Feb. 3: The discoverers, who, though working in pairs, were dividing mates, have applied for a claim which all hope will prove a ‘bonza’.
1906		Gadfly (Adelaide) 12 Dec. 842/1: ‘Grand weather?’ I remarked. / ‘It’s a bonzer!’ he answered, with enthusiasm.
1908		E.G. Murphy ‘Apples’ in Jarrahland Jingles 164: The banquet was a bonza, a rare recherche feed.
1911		E. Dyson ‘Barracking’ in Benno and Some of the Push 140: Loud ’n’ large opinions t’ th’ effect that St. Kilda is the dazzlin’ P., the bonzers, the boshters, the pink, the pride, ’n’ the pick iv th’ earth. [Ibid.] ‘Benno, yer a fair bonza!’.
1912		Catholic Advocate (Brisbane) 12 Oct. 18/3: His kicking was magnificent, one of the penalty goals being a real ‘bonzor’.
1914		A. Wright In Last Stride 14: Blime, th’ car’s a bonser; travel! why, she bloomin’ well flies [AND].
1915		Sport (Adelaide) 12 Feb. 5/7: Fid looked a bonzar in those icecream trousers.
1915		Honk! 4 Jan. 4/2: Have you heard about the paper / I presume its newly born [...] And its coming very shortly, / But I hope it don’t go plonk, / And its going to be a bonza.
1918		Aussie (France) Apr. 2/1: And I tell yer it’s a bonzor w’en we’re feeling cold and stunned / And we trudges for our issue ter the little ‘Comforts Fund’ [AND].
1927		Canberra Community News 11 Apr. 5: The returned ‘Diggers’ social last month was a ‘bonzer’ [AND].
1931		‘William Hatfield’ Sheepmates 164: I’m going to learn to say ‘My bloody oath!’ and ‘Dinkum, Bonzer’.
1934		North. Standard (Darwin, NT) 3 July 7/3: The one [i.e. a lizard] I spoke of last week is a bona — or bonzarina.
1943		Baker ‘Influence of American Sl. on Australia’ in AS XVIII:4 256: A wow or hummer is a bonzer or whopcacker.
1942		Dly News (NY) 30 May 10/3: In Australia [...] if a thing is a bonzer it’s tops.
1960		S. Woodfield A for Artemis 21: ‘I’ve put a bit on the side for yer Maggie,’ he used to say. .. ‘A coupla nice kidneys, Maggie, real bonzers.’ [AND].

2. an expert; an admirable person; a beautiful woman.

1903		Sportsman (Melbourne) 22 Sept. 3/4: As one racer said to me. ‘Ain’t he a bonsor!’‘Bonsor,’ though anything but euphonious slang, hits it right.
1904		Sun. Times (Perth) 18 Dec. 4/8: One lady in particular seemed to have created a ‘corner’ in male admiration and female envy. She was what they call in the classics a ‘bonzer’.
1906		E. Dyson Fact’ry ’Ands 182: What’s er bonzer like you doin’ spreadin’ sour paste fer yer daily?
1912		Sport (Adelaide) 19 Oct. 13/4: They Say [...] That ‘Billie R.’ caught a ‘bonzer’ off the corner last week [...] She was a beaut (we don’t think), .
1913		Sport (Adelaide) 22 Mar. 12/1: They Say [...] That Joe H [...] is a bonza at hamming stripes and is now going up for Crowns.
1915		Eve. Post (Wellington) 10 Sept. 6: ‘I wish I knew where that kid is now: he was a bonzer!’.
1918		Aussie (France) 5 June 4/2: You can laugh if you like, but she was a bonza.
1920		Advocate (Burnie, Tas.) 5 June 7/2: Snorkey, you’re a snitty bonser! Tres beans! A snifter.
1924		Mail (Adelaide) 16 Feb. 1/5: If small boys, and their elder brothers too, desire to bestow praise upon some idol of the playing fields they shout a raucous query at the sky. ‘Is he any good?’ they ask of nobody in particular. It is their way of saying he’s a ‘bonza’.
1928		A.W. Upfield House of Cain 19: Say — isn’t she a bonzer!
1934		T. Wood Cobbers 87: ‘She’s a bonza,’ said Mr. Dean, jerking his head towards the door through which the flower-girl had withdrawn.
1943		J.A.W. Bennett ‘Eng. as it is Spoken in N.Z.’ in AS XVIII:2 Apr. 89: There is a liking for words in -er, and a whole group of them express admiration: [...] bosker, and bonzer; the last was certainly borrowed from Australia.
1972		B. Fuller West of Bight 18: A suitable caravan turned up at last... ‘She’s a bonzer. I guess you’ll be lucky.’.

3. in adv. use, vigorously, enthusiastically.

1904

Argus (Melbourne) 4 June 5/8: ‘How did I barrack, eh?’ I say gleefully to my son. ‘You barracked a bonza,’ he answers, ‘but there were moments when I was ashamed of you!’.