back out of
(PW)
withdraw, end an obligation or promise
I made a deal with my friend to help him at work. When I became too busy, I had to back out of it.
(MW)
to withdraw especially from a commitment or contest
(die.net)
v 1: move out of a space backwards; "He backed out of the driveway"
2: 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" [syn: retreat, pull back, back away, crawfish, crawfish out, pull in one's horns, withdraw]
(UsingEnglish)