Antonyms for the phrase "give one's word" include "break a promise," "renege," "go back on one's word," and "fail to keep one's word." These antonyms express the opposite meaning of making a firm commitment or assurance to follow through on a promise or guarantee. Instead, they suggest that the person has failed to uphold their obligation, resulting in a breach of trust and a lack of credibility. When one gives their word, it is essential to follow through with their commitments to maintain integrity and trustworthiness. Conversely, breaking one's word can lead to damaged relationships and a loss of trust.