1) Backs out 2) Backs out on a deal 3) Breaks a promise 4) Breaks promise 5) Bridge blunders 6) Bridge misplays 7) Commits an act of betrayal 8) Cops out 9) Defaults as on a promise 10) Fails to come through 11) Fails to follow suit 12) Faux pas at bridge 13) Goes back 14) Goes back on 15) Goes back on a promise 1) Cops out 2) Welshes