'human-only' originates from Modern English, specifically a compound of the adjective 'human' and the adverb/adjective 'only'. 'human' ultimately comes from Latin 'humanus' meaning 'of man, human', and 'only' from Old English 'ānlic' (related to 'ān' meaning 'one').

'human' entered English via Old French 'humain' from Latin 'humanus' and developed in Middle English; 'only' developed from Old English 'ānlic'. The compound 'human-only' is a modern English coinage formed by joining these elements to express restriction to humans.

Initially, 'human' meant 'of man' and 'only' meant 'single' or 'one'; combined in modern usage they explicitly express the sense 'limited to humans' without major semantic shift of the original elements.