Un-faltering means unwavering or steadfast, and its antonyms include faltering, vacillating, wavering, indecisive, unsure, and fluctuating. Faltering implies a lack of confidence or hesitation, while vacillating suggests a lack of commitment or a tendency to change one's mind. Wavering suggests instability or inconsistency, while indecisive implies a difficulty in making up one's mind. Unsure suggests a lack of certainty or confidence, while fluctuating suggests changes in intensity or direction. In contrast, un-faltering implies a strong sense of resolve, determination, and commitment. Antonyms of un-faltering thus describe a lack of stability or consistency in one's attitudes or actions.