showdown (n.)youdaoicibaDictYouDict[showdown 词源字典]
also show-down, 1873 in card-playing (especially poker) a slang term for the act of laying down the hands face-up, from show (v.) + down (adv.). Figurative sense of "final confrontation" is from 1904.[showdown etymology, showdown origin, 英语词源]