turn back

柯林斯词典

1. PHRASAL VERB If you turn back or if someone turns you back when you are going somewhere, you change direction and go toward where you started from. 往回走
She turned back toward home. 她折了回来往家走去。
Police attempted to turn back. 警察试图往回走。
2. PHRASAL VERB If you cannot turn back, you cannot change your plans and decide not to do something, because the action you have already taken makes it impossible. (无法) 回头[with brd-neg]
The Senate has now endorsed the bill and can't turn back. 参议院现已同意了该议案，无法回头了。