turn back

英 [tɜːn bæk]

美 [tɜːrn bæk]

（使）返回; （使）折回; 无法改变计划; 无法收回成命

牛津词典

以上各词均含回来、回去、返回之义。
These words all mean to come or go back from one place to another.
指回来、回去、返回：
to come or go back from one place to another
1. I waited a long time for him to return.
  我等他回来等了很长时间。
指回来、返回
to return
指回去、返回
to return to the place you recently or originally came from or that you have been to before
指返回、回去，尤指回家：
to arrive back somewhere, especially at your home or the place where you are staying
1. What time did you get back last night?
  你昨晚什么时候回家的？
指原路返回、往回走，尤指因某事阻止而不能继续前进：
to return the way that you came, especially because sth stops you from continuing
1. The weather got so bad that we had to turn back.
  天气变得非常恶劣，我们不得不循原路折回。

PHRASAL VERB-ERG (使)返回;(使)折回
If youturn backor if someoneturnsyoubackwhen you are going somewhere, you change direction and go towards where you started from.
1. She turned back towards the crossroads...
  她折回十字路口。
2. They were very nearly forced to turn back...
  他们差点被迫返回。
3. Police attempted to turn back protesters marching towards the offices of President Ershad.
  警方试图迫使向艾尔沙德总统官邸进发的抗议者原路返回。
PHRASAL VERB 无法改变计划;无法收回成命
If youcannot turn back, you cannot change your plans and decide not to do something, because the action you have already taken makes it impossible.
1. The administration has now endorsed the bill and can't turn back.
  政府部门如今已经签署了那项法案，没有挽回的余地。

verb

turn inside out or upside down
Synonym:invertreverse
go back to a previous state
1. We reverted to the old rules
Synonym:revertreturnretrovertregress
hold back, as of a danger or an enemy
1. Arrest the downward trend
2. Check the growth of communism in South East Asia
3. Contain the rebel movement
4. Turn back the tide of communism
Synonym:checkarreststopcontainhold back
force to go away
1. Drive away potential burglars
2. drive away bad thoughts
3. dispel doubts
4. The supermarket had to turn back many disappointed customers
Synonym:chase awaydrive outdrive awaydispeldrive offrun off
retrace one's course
1. The hikers got into a storm and had to turn back
Synonym:backtrackdouble back

I know it is kind of late, but I can't turn back time.
我知道有点迟了。但我无法时光到转。
Do you think that now, I can still turn back?
你以为到了现在，我还回得了头么？
The horsemen reined in and shouted at the men behind to turn back
骑手们勒缰停住，对身后的人大嚷，让他们回去。
His group was forced to turn back and take an alternate route.
他的小组被迫返回并选择了另一条路线。
They were very nearly forced to turn back
他们差点被迫返回。
I always behind you, when you turn back, you will see me.
我永远在你背后，只要你转头，你就会看见我。
Turn back? Now? But we don't know what's on the next floor!
你让我们趁现在就回来？可是我们还不知道下一层楼有什么东西呢！
But having come so far she was determined not to turn back.
但是，都走了这么远的路了，所以她决定不回去了。
I mean just turn back and give me your hand when I'm ready.
我是说你转过去，等我准备好的时候借手给我。
Finding the road impassable, we had to turn back.
道路不通，我们只得退回。