Antonyms for the phrase "giving one's word" could include breaking a promise, lying, dishonesty, falsehood, deception, unreliability, and untrustworthiness. These words highlight the negative consequences that can arise when someone fails to keep their word, especially in relationships, business affairs, or social interactions. Breaking one's promises can lead to disappointment, loss of trust, and damage to one's reputation. Therefore, it is essential to honor one's commitments, follow through on promises, and communicate truthfully to build and maintain a strong sense of integrity and credibility in one's personal and professional life.