shì​bù​fǎn​huǐ

to vow not to break a promise

  1. to swear
    (bound form) to swear; to vow; to pledge to follow through on one's word
  2. adverb
    not
    Negative adverb used before verbs, adjectives, and other adverbs to indicate negation; also used as a bound-form prefix to form terms with opposite meanings
  3. to go back on one's word
    To renege or back out of a previous promise, deal, or agreement; to have second thoughts and change one's mind about a commitment.