down and out  精疲力尽； 穷困潦倒；完蛋

这个比喻来自拳击，拳击手被对手击倒，而不能在数完数字前起来，就等于被击败而不能再比赛。

例： The man was obviously down and out, so we gave him a meal and sixpence. 这人显然穷困潦倒，所以我们给他吃一顿饭，并给他六便士。