back out

动词verb

1. 1transitiveTo reverse (a vehicle) from a confined space.
2. 2intransitiveTo withdraw from something one has agreed to do.
3. 3transitiveTo convince (someone) to withdraw from a challenge.
4. 4(gambling) To bet on someone losing.
5. 5(computing, transitive) To undo (a change).
6. 6(computing, intransitive) To exit a mode or function.
7. 7MLE, transitiveTo draw from behind the back (a knife etc.) (as also bare back).