It implies a dishonorable act of breaking your word, often when it is advantageous to do so.
Here are some examples:
* "After agreeing to the deal, the company reniqued on their promise to invest in the project."
* "He reniqued on his commitment to help me move, leaving me stranded with a mountain of boxes."
* "She reniqued on her vow to never eat sweets again, after seeing a delicious chocolate cake."
The word "renig" is often used in a negative context, implying that the person who broke the promise is untrustworthy or dishonest.