Definition

1. Verb:
   • To break one's promise / to fail to keep one's word: The core meaning of "thất tín" is to not do what one has promised to do, thereby violating a commitment or agreement.
   • To be untrustworthy / to lose credibility: It describes the resulting state where trust is broken because of a failure to honor one's word.

Usage Examples

• Verb:
  • Đừng bao giờ thất tín với đối tác. (Never break your promise to a partner.)
  • Anh ấy thất tín nên không ai muốn hợp tác nữa. (He failed to keep his word, so no one wants to cooperate with him anymore.)
  • Một lần thất tín, vạn lần bất tin. (A single failure to keep your word leads to endless distrust. [Vietnamese proverb])

Advanced Usage

• "Kẻ thất tín": an untrustworthy person, a promise-breaker.
  • Trong kinh doanh, bị coi là kẻ thất tín là dấu chấm hết. (In business, being labeled a promise-breaker is the end.)

Variants and Related Words

• Thất hứa (v): to break a promise. This is a very close synonym, often used interchangeably with "thất tín."
  • Anh ta đã thất hứa về thời hạn giao hàng. (He broke his promise about the delivery deadline.)

Synonyms

• Break a promise: to fail to keep a promise.
• Go back on one's word: to not do what one said one would do.
• Be unfaithful to an agreement: to violate the terms of an understanding.

Related Idioms and Proverbs

• "Một lần bất tín, vạn lần bất tin": This proverb emphasizes the severe and lasting consequence of breaking trust: "One breach of faith, ten thousand losses of trust."

verb

1. fail to keep one's word