double back

动词 double back:

1. retrace one's course
   同义词：backtrack, turn back

1. The road ahead was flooded so we had to double back.
   前面的路已遭水淹，我们只好原路折回。
2. The road ahead is flooded so we have to double back.
   前面的路已遭水淹，我们只好原路折回。