Green’s Dictionary of Slang

1. a contraption made of a selection of disparate bits and pieces; also attrib.

1922		Australasian 11 Feb. 49/5: B. Morris, on a machine of his own construction, qhich he calls the ‘Bitza’.
1924		Smith’s Weekly (Sydney) 6 Dec. 24/5: Toombes built the body himself, and made a fair job of it. Thence emerged the super Bitza [...] and those who do not know that its ragged bonnet hides a Vauxhall engine ponder over the origin of its cheek [AND].
1927		Truth (Wellington) 29 Dec. 13: A man bought a car after some study of the merits and demerits of a number in the competitive price Held, and finally decided on a Bitza.
1935		Land (Sydney) 30 Aug. 14/5: I don’t think there is anyone who does not know what a ‘Bitza’ is [...] it is a car which is home-made out of the parts of anything up to a dozen different makes.
1937		Queenslander (Qld) 18 Mar. 44/2: A ‘BITZA’ RADIO SET. Mr. Meredith, of Liverpool, England, has built a radio set out of old tins, a bottle a clothes peg, a cigarette, and some razor blades—and it works!
1939		China Digest 53: [I] saw it was a benz [...] and i nickenamed it ‘The Bitser’ — bitser tin and bitser wire were doing the job of so many of its parts.
1940		(ref. to 1926) Sporting Globe (Melbourne) 10 July 11: I won the Veterans' ‘Austral’ Wheel Race [...] in 1926 [...] on what some termed a ‘bitzer,’ the bicycle was composed of famous parts used by world-famed riders.
1951		S. Hickey Travelled Roads 27: George had a big ‘bitza’ clock with a powerful knock at each hour, but it struck one every time [AND].
1988		McGill Dict. of Kiwi Sl. 15/1: bitser made from bits and pieces, such as mongrel or home-made trolley.
2000		Indep. Rev. 29 Jan. 20: To be honest, it’s what the motor trade calls a ‘bitza’.
2003		McGill Reed Dict. of N.Z. Sl. [as cit. 1988].

2. a mongrel dog; by ext. any ‘mongrel’; also attrib.

1934		Bunyip (Gawler, SA) 18 May 4/4: ‘What kind Of a dog is he?’ [...] ‘I think he must be a bits of evervthing,’ she said, ‘my friends call him a bitzer’.
1940		Bulletin (Sydney) 6 Nov. 17/4: Joe the rouseabout [...] not only refused to acknowledge the canine as a blue-blooded poodle, but also made a few tactless references to ‘bitzers’.
1952		Cumberland Argus (Paramatta, NSW) 23 Jan. 1/2: ‘IT'S BEEN A GREAT ADVENTURE, but I'm really sorry. I caused mistress (Mrs. Marge Coombs,- of George Street, Parramatta) so much unhappiness,’ Twinkle, three-years-old: lovable bitza, said today.
1953		Advertiser (Adelaide) 8 June 4/7: Lost and found. — Lost dog. strayed, a black bitser, friendly pup, answers to name Rexy.
1967		Canberra Times (ACT) 29 Apr. 3/3: A ‘bitzer’ dog gave blood yesterday to have the life of a tiny Toorak poodle, Sanci, who was dying of septicaemia.
1969		C. Himes Blind Man with a Pistol (1971) 90: His eyes had a slight Mongolian slant, giving his face a bitsa look, a bit of African, a bit of Nordic, a bit of Oriental.
1973		J. Waten Bottle-O! 38: He had a dog himself. His father said it was a bitzer. [...] He said it had a bit of this and a bit of that.
1986		R. Beckett Dinkum Aussie Dict. 8: Bitzer: A dog consisting of many breeds, a mongrel. A bit of this and a bit of that.
1986		C. Bowles G’DAY 1: The Fosters have a pet dog called Scungeball. It's a bitser.
1988		see sense 1.
1990		S. Geason Shaved Fish 126: The dog was the regulation ugly student bitser.
2000		Star Gaz. (Elmira, NY) 11 Sept. 26/1: Australian slang [...] Bitzer: mongrel dog (as in bits of this, bits of that).
2008		P. Carey His Illegal Self 72: I’m a bitzer, she said [...] Bits of this and bits of that.
2019		C. Hammer Silver [ebook] [T]he mongrels and bitsers that roamed the neighbourhood.