enemy [ME] An enemy is not your friend. So far, so obvious, but this is, in fact, the derivation of the word. It came into the language at the end of the 13th century from Old French enemi, from Latin inimicus, which was based on in- meaning ‘not’ and amicus ‘friend’. Inimicus is the source of inimical [E16th] or ‘hostile’, and amicus of amicable [LME] or ‘friendly’.