Green’s Dictionary of Slang

1. (Aus./N.Z.) unreliable, dishonest, ‘crooked’; thus one who is engaged in irregular or illegal business activities.

1969		B. Breydor You Oughta Seen Us! 86: [T]he Snob’s been palmed off shonky notes.
1985		B. Humphries Traveller’s Tool 18: A few nosey investigators started querying the shonky books.
1986		R.G. Barrett Real Thing 69: Insults about fred being a shonky copper.
1996		P. Temple Bad Debts (2012) [ebook] Old Joe’s the biggest donor to that shonky foundation of his.
2000		P. Temple Dead Point (2008) [ebook] Cyril’s deeply shonky [...] but this [i.e. violence], no.
2003		McGill Reed Dict. of N.Z. Sl. 187: shonky Dodgy or unsafe, as in pyramid salesmen or the rotting walls of new houses. [...] probably derived from ‘shonk’, abbreviation of shonicker, an offensive name for a Jew.
2012		(con. 1943) G.S. Manson Coorparoo Blues [ebook] [The goods] never got near no bloody hospital, for obvious shonky reasons.
2014		Observer Rev. 26 Jan. 12/3: The pictures are variously brilliant, shonky, confident, bungled.
2017		Sun. Times 26 Feb. 🌐 Milo, 32, has been unmasked as a classic prat and a liability. But his shonky behaviour comes as no surprise.

2. (Aus.) a a piece of equipment, run down, worn out.

1986

C. Bowles G’DAY 64: [of a car] Sounds a bit shonky ter me. Reckon emusta flogged it.