'australianize' originates from Modern English, specifically the word 'Australian' plus the suffix '-ize', where 'Australian' derived from 'Australia' (from Latin 'australis' meaning 'southern') and the suffix '-ize' comes from Greek '-izein' meaning 'to make or become'.

'australianize' was formed in English by attaching the productive verb-forming suffix '-ize' to 'Australian' (itself from 'Australia', from Neo-Latin usage such as 'Terra Australis'); the modern verb form emerged in the 19th century as English created verbs meaning 'make X'.

Initially it meant 'to make or become Australian (in character or style)', and over time the basic meaning has remained largely consistent, used both transitively and intransitively.