'anti-foreign' is a compound formed from the prefix 'anti-' and the adjective 'foreign'. 'anti-' originates from Greek 'anti-' meaning 'against, opposed to', and 'foreign' comes via Old French 'forain' (and ultimately Latin) referring to 'outside' or 'from abroad'.

'foreign' developed from Old French 'forain' and Latin 'foris' meaning 'outside'; over time Old English and Middle English forms merged into modern English 'foreign'. The prefix 'anti-' comes from Greek and entered English through Latin and later borrowing, combining with nouns and adjectives to mean 'against'. These elements combined in modern English to form compounds like 'anti-foreign'.

Initially, the elements meant 'against' (for 'anti-') and 'outside' or 'from abroad' (for 'foreign'); together they have long conveyed opposition to foreigners or foreign influence, a meaning that has remained consistent.