suffusion (n.)youdaoicibaDictYouDict[suffusion 词源字典]
late 14c., from Latin suffusionem (nominative suffusio) "a pouring over," noun of action from past participle stem of suffundere "pour upon, overspread, suffuse," from sub "under" (see sub-) + fundere "to pour" (see found (v.2)).[suffusion etymology, suffusion origin, 英语词源]