Green’s Dictionary of Slang

(orig. Aus.) a threepenny piece.

1895		Dly Northern Argus (Rockhampton, Qld) 4 July 3/7: The violin, case and all, sank to the bottom, and the Duke was in despair. [...] I have only a sovereign and two shilling left, but if anyone can put a hook down and fish it up, the money is theirs. I’ll cop yer fiddle, mister, said a shrill juvenile voice at his elbow [...] If ye’ll stand the jimmy yer kin collop the two peg for a boose after.
1920		Sun (Sydney) 12 Oct. 8/1: ‘What is a ‘trizzie’?’ asked Sergeant White at the Central Police Court this morning. It was explained to him that it was the latest term for a threepenny bit.
1929		Narromine News (NSW) 25 Oct. 9/5: Sing a song o’ threepence, / Here’s a great profession, / Sweeps another ‘trizzie’ / Into its possession.
1939		Uralla Times (NSW) 13 Apr. 1/4: Anyhow, wouldn’t it be a queer feeling to have that drip! drip! drip! - to feel that you were being ‘bled’ and that you could clear it all away by not spending a nimble ‘trizzie’? once a week! fifty-one times a year!
1941		Baker Popular Dict. Aus. Sl. 78: Trizzie, a 3d. piece.
1953		D. Cusack Caddie 216: ‘I’m sure I ’ad another trizzy somewhere,’ he frowned and made a great show of going through his pockets.
1955		N. Pulliam I Travelled a Lonely Land (1957) 241/1: tray (trezzie, trizzie) – a threepence; sometimes, three years in jail.