clincher (n.)youdaoicibaDictYouDict[clincher 词源字典]
early 14c., "person or thing that clinches" (i.e., secures nails by bending down or riveting the pointed end), late 15c. as a class of shipyard worker; agent noun from clinch (v.). As a type of nail, from 1735; as a conclusive statement, argument, etc., 1737.[clincher etymology, clincher origin, 英语词源]