reneged

chickened (out), wimped out

backpedaled, backtracked

abjured, abnegated, disavowed, forswore (also foreswore), recalled, recanted, repudiated, retracted, took back, unsaid, withdrew

begged off, cried off [chiefly British]

contradicted, denied, disavowed, disclaimed, disowned, gainsaid, negated, negatived

abandoned, bolted, forsook, gave up, relinquished, spurned, surrendered

controverted, disagreed (with), disproved, disputed, rebutted, refuted

backed down, backed off, backtracked

disallowed, recalled, revoked