turn (sb/sth) back
(cause sb/sth to) return the way he/it has come (使某人[某物])循原路折返, 往回走
The weather became so bad that they had to turn back. 天气变得很坏, 他们只好原路而归了.
(fig 比喻) The project must go ahead; there can be no turning back. 这计画必须坚持下去, 不能打退堂鼓.
Our car was turned back at the frontier. 我们的汽车在边境处被勒令折返.