"Word of honour" is a phrase that represents a solemn promise made by someone. It is often used as a pledge to confirm the truthfulness and trustworthiness of the speaker. Some of the synonyms for "word of honour" include "sworn promise," "oath," "commitment," "bond," "vow," "guarantee," "assurance," "pledge," "declaration," "affirmation," and "solemn undertaking." These words signify a commitment that is taken seriously and bound by values such as honesty and integrity. By using these synonyms instead of the phrase "word of honour," individuals can convey the same gravity and importance of their promise, thereby emphasizing the significance behind their commitment.