1. To force or be forced into a difficult or unpleasant situation that one cannot easily resolve or escape. A noun can be used between "back" and "into." My boss really backed me into a corner when he asked me to fire the CEO's daughter.Scott has been backed into a corner with this mortgage payment that he cannot afford.
2. To put oneself into a difficult or unpleasant situation that one cannot easily resolve or escape. In this usage, a reflexive pronoun is used between "back" and "into." I really backed myself into a corner when I agreed to go to two events on the same night.