Green’s Dictionary of Slang

1. (US) a despicable person.

1843		Gleaner (Manchester, NH) 11 Mar. n.p.: I believe that ten people could not be found [...] foolish enough to pay one copper to have this canine cockroach read copyings from old books.
1889		Dead Bird (Sydney) 14 Sept. 5/1: [of moral reformers] Mr Varley and all his black cockroaches .
1890		H. Lawson ‘Possum’ in Roderick (1967–9) I 81: No, he wa’n’t the kind er cockeroach that on’y kums ter shirk.
1935		(con. late 1920s) L. Hughes Little Ham III i : ham: Who you callin’ a runt? gilbert: You, you stunted cockroach!
1945		R.S. Close Love me Sailor 45: You ruttin’ greeping gockroach! Vot vor you greep after me?
1953		R. Chandler Long Good-Bye 174: A good man died for me once, why not a cockroach in a white jacket?
1968		‘Hy Lit’ Hy Lit’s Unbelievable Dict. of Hip Words 9: clod – A total square; a hopeless cockroach who is so un-hip and he ain’t wrapped too tight, and he never will be.
1983		C. Heath A-Team 2 (1984) 131: Who’s the two hundred pound cockroach?
1990		(con. early 1950s) J. Ellroy L.A. Confidential 25: You fucking cockroach.
2009		N. Flexner Disassembled Man [ebook] Blowing kisses to all the cockroaches and maggots that were hanging from chairs .
2011		Mail and Guardian (Johannesburg) 29 Apr. 🌐 he called Helen Zille a cockroach and hit my mother in the face.
2011		Mail and Guardian (Johannesburg) 16 Feb. 🌐 Tutsis were referred to as ‘cockroaches’ by Hutu militia.
2017		T. Spicer Good Girl Stripped Bare 22: Queenslanders are more excited about being on the telly than the people we call ‘cockroaches’ down south.

2. (Aus.) a native of New South Wales.

2022

D. Andrew Aussie Sl. 10: Cockroaches Residents of New South Wales.