Source : WordNet®

back out
     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}]