Green’s Dictionary of Slang

ethno n.

[SE ethnic + -o sfx (3)]

(Aus.) immigrants to Australia, of various ethnic persuasions.

[Aus]Sydney Morning Herald 18 Aug. 1: There’s been a backlash against the widespread use of the word ‘ethnic’. A social worker with the Department of Social Security tells us that school pupils are now calling migrants ‘ethnos’ [GAW1].