mordant n. + Add to list US //ˈmɔɹdənt// UK //mˈɔːdənt// mor·dant SynonymsEtymology Synonyms blackcausticcorrosiveerosivegrimvitriolicOriginLATmordeō→FRAmordant→ENmordant From French mordant, from Latin mordeō. Doublet of mordent.