PlacidylWiktionary 原文英美构词拆解Placidplacid词干yl-yl后缀-yl(organic chemistry) A univalent radical or functional group formed from a given molecule. Thus propyl from propane, benzyl from benzene, and so forth.词源说明Marketing name, apparently from placid + -yl.释义名词noun1(pharmacology) Trade name of ethchlorvynol, a sedative.