To go back on Meaning, Definition & Usage

Definitions
  1. . (a) To retrace (one's path or footsteps). (b) To abandon; to turn against; to betray. Slang, U. S.
Definitions
  1. to turn back from; to abandon; to betray; as, to go back on a friend; to go back on one's professions. Colloq.

Webster 1913