Green’s Dictionary of Slang

Rhodes scholar n.2

[rhy. sl. = dollar n.1 (1)]

(Aus.) five shillings.

[Aus]Argus (Melbourne) 13 June 4s/3: Here we have the ‘John Dillon’, and [...] ‘hammer and tack’ for ‘zac’ (6d.) and ‘Rhodes scholar’ for ‘dollar’ (5/-).