Green’s Dictionary of Slang

(orig. Aus.) a general intensifier; esp. as (stone) motherless broke, completely bereft of funds.

1900–10		Stephens & O’Brien Materials for a Dict. of Aus. Sl. [unpub. ms.] 99: MOTHERLESS: comparative: motherless broke, motherless stiff.
1908		Sun. Times (Perth) 1 Mar. 4/8: I’m dead, stone, motherless broke.
1912		Bulletin (Sydney) 10 Oct. 16/3: Promptly a pretty party of Perth pirates palled in with Yorky, and he returned to the Immigrants’ Home at dewy eve, stone, motherless broke.
1928		Age (Melbourne) 11 Oct. 11/5: In the words of the ‘down and out,’ we would very soon be ‘stone motherless broke’.
1931		Age (Melbourne) 21 July 8/5: He said he was ‘stone motherless broke’.
1947		Sydney Morn. Herald 7 Mar. 7/3: He would not be paying out [...] reluctant to be again [...] stone motherless broke.
1951		Cusack & James Come in Spinner (1960) 17: I know what it is to be stone motherless broke in a strange city.
1959		Age (Melbourne) 25 Aug. 5/5: The wife arrived home [...] ‘stone, motherless broke’ — after paying opff the poker machines.
1961		R. Gover One Hundred Dollar Misunderstanding 34: Don’ be no mothahless whole night fer one dum five-bill College Joe.
1967		‘Whisper All Aussie Dict.’ in Kings Cross Whisper (Sydney) xl 4/5: stone motherless: Stone broke. Penniless.
1971		Sydney Morn. Herald 21 Mar. 9/4: ‘I’d go on betting and walk off the track stone motherles sbroke’.
1982		Syndey Morn. Herald 3 May n.p.: Mr Packard [...] arrived in Australia from England fifteen years ago ‘stone motherless broke’.
1986		C. Bowles G’DAY 7: Shane and his friend Macka are going to the disco. [...] Shane is Stone Motherless but has put the bite on his old man for ten bucks.
1996		Penguin Bk of More Aus. Jokes 26: She’s stone, motherless broke.
1996		P. Temple Bad Debts (2012) [ebook] I’ve had a coup horse run last. Stone motherless last.