bottleneck (n.)youdaoicibaDictYouDict[bottleneck 词源字典]
also bottle-neck, "narrow entrance, spot where traffic becomes congested," 1896; from bottle (n.) + neck (n.). Meaning "anything which obstructs a flow" is from 1922; the verb in this sense is from 1928.[bottleneck etymology, bottleneck origin, 英语词源]