'Austrian' originates from German, ultimately from Old High German 'Ostarrîchi' (rendered in Medieval Latin as 'Austria'), where 'ost-' meant 'east' and 'rîchi' meant 'realm' or 'territory'.

'Austrian' developed from the place name 'Austria' (Medieval Latin 'Austria'), which itself comes from Old High German 'Ostarrîchi' ("east realm"). Over time the place-name entered English as 'Austria' and the adjective/noun form 'Austrian' followed.

Initially the element referred to the 'eastern realm' (a geographic/political region); over time it came to denote the modern nation of Austria and things or people originating from there, which is the current meaning.