impetuous adj. + Add to list US //ˌɪmˈpɛtʃwəs// UK //ɪmpˈɛtʃuːəs// im·petu·ous SynonymsEtymology Synonyms brainishhotheadedimpulsivemadcaptearawayOriginLATimpetus→LA-LATimpetuōsus→OFRimpetueux→MEimpetuous→ENimpetuous From Middle English impetuous, from Old French impetueux, from Late Latin impetuōsus (“violent”), from Latin impetus (“attack, violence”).