Green’s Dictionary of Slang

(Aus.) to act in a cowardly way.

1919		W.H. Downing Digger Dialects 42: ring it — Play the coward.
1924		(con. WWI) A.G. Pretty Gloss. Sl. [...] in the A.I.F. 1921–1924 (rev. t/s) n.p.: ring it or ring his tail. Play the coward.
1955		N. Pulliam I Travelled a Lonely Land (1957) 238/1: ring it – be a coward.
1977		G.F. Newman A Prisoner’s Tale 133: ‘He always was a snaky cunt, that one,’ he said now, ringing it to disassociate himself from the DI.