Having no way out; having one's back to the wall—no room for error or no second chance left.
資金が底をつき、もう後が無い。何とか追加の融資を受けなければならない。
Funds have run out and there's no way out now. We must somehow get additional financing.
この試合に負ければ後が無いから、全力で挑むつもりだ。
If we lose this match we'll have no chance afterward, so we're going all out.
彼は言い訳を続けたが、証拠が揃っていて後が無いと悟ったようだ。
He kept making excuses, but with the evidence mounting he seemed to realize he had no way out.