'virilize' originates from Latin, specifically the word 'virilis', where 'vir' meant 'man' and the adjectival suffix '-ilis' formed 'virile'; the English verb-forming suffix '-ize' (from Greek '-izein' via Late Latin/Old French) means 'to make'.

'virilis' passed into Late Latin and Old French as 'viril' and English adopted 'virile' from these sources; the verb 'virilize' was formed in modern English by adding the productive suffix '-ize' to the stem related to 'virile'.

Initially it was an adjective meaning 'manly' or 'pertaining to a man', but it evolved into a verb meaning 'to make manly' or 'to cause masculinization'.