fifth wheel
多余的人或物
口语·形容多余或累赘
英文释义
someone or something that is unnecessary, redundant, or superfluous in a particular situation
例句
I felt like a fifth wheel at their couple's dinner.
典故来源
源自马车上的第五个轮子，实际无用，比喻多余或无关紧要的人或物。