- In Australian English an illywhacker (or illywacker) is a small-time confidence trickster. The origin of the term is unknown. Sidney Baker in The Australian Language (1945) suggested that the first part of the word may be a corruption of spieler. Our earliest written evidence for the term occurs in Kylie Tennant's The Battlers (1941): An illy-wacker is someone who is putting a confidence trick over, selling imitation diamond pins, new-style patent razors or infallible 'tonics'... 'living on the cockies' by such devices, and following the shows because money always flows freest at show time. A man who 'wacks the illy' can be almost anything, but two of these particular illy-wackers were equipped with a dart game. This is a term which was becoming obsolescent in Australian English, but it was given new life when Peter Carey used it as the title of his 1985 novel. In that novel, we find the following passage: What's an illywhacker?'... 'A spieler.. a trickster. A quandong. A ripperty man. A con-man.
Australian idioms. 2014.