ardor n. + Add to list US //ˈɑɹdɝ// UK //ˈɑːdɔː// ar·dor SynonymsEtymology Synonyms elanfervencyfervidnessfervorfirezealOriginLATardor→OFRardur→XNOardour→MEardour→ENardor From Middle English ardour, ardowr, ardure, from Anglo-Norman ardour, from Old French ardur, from Latin ardor, from ardere (“to burn”).