'masculine-looking' originates from Modern English, specifically the words 'masculine' and 'looking', where 'masculine' ultimately comes from Latin 'masculinus' (from 'masculus') meaning 'male', and 'looking' derives from Old English 'lōcian' meaning 'to look or seem'.

'masculine' changed from Latin 'masculinus' (from 'masculus') through Old French/Medieval French 'masculin' into Middle English and then modern English 'masculine'; 'look' comes from Old English 'lōcian' which evolved into Middle English forms and eventually modern English 'look', with the participial form 'looking' used to mean 'appearing'.

Initially, the roots meant 'male' (for 'masculine') and 'to direct one's gaze or to seem' (for 'look'); over time the compound came to mean 'appearing masculine' or 'having a masculine appearance'.