Renege

[rɪ'neɪg;rɪ'niːg] or [rɪ'niɡ]

(verb.) fail to fulfill a promise or obligation; 'She backed out of her promise'.

Editor: Priscilla--From WordNet

(v. t.) To deny; to disown.

(v. i.) To deny.

(v. i.) To revoke.

Checker: Nanette