'pro-nationally' originates from English, specifically formed from the prefix 'pro-' (from Latin 'pro') meaning 'for', the adjective 'national' (from French 'national', ultimately from Latin 'natio') and the adverbial suffix '-ly' (from Old English '-lic').

'national' changed from French 'national' and Latin 'natio' ('birth, people'), and the compound 'pro-national' was extended with the English adverbial '-ly' to form 'pro-nationally' in modern English.

Initially it meant 'for the nation' or 'in favor of national interests'; over time the phrase has retained this core meaning and is used to describe actions or attitudes that support nationalism or national priorities.