back out (verb)

move out of a space backwards

"He backed out of the driveway"

retreat, pull back, back out, back away, crawfish, crawfish out, pull in one's horns, withdraw (verb)

make a retreat from an earlier commitment or activity

"We'll have to crawfish out from meeting with him"; "He backed out of his earlier promise"; "The aggressive investment company pulled in its horns"

back out (Verb)

To reverse a vehicle from a confined space.

back out (Verb)

To withdraw from something one has promised to do.

back out (Verb)

To undo a change.