Constancy refers to the quality of being consistent, unchanging and dependable. Some synonyms for the word constancy include steadfastness, faithfulness, reliability, continuity, consistency, steadfastness, and endurance. Steadfastness implies unwavering determination and loyalty, while faithfulness suggests a loyal and committed relationship. Reliability refers to the consistency and predictability of a person or thing. Continuity refers to something that persists and remains unchanged over time. Consistency implies that something is always the same and unchanging, while steadfastness suggests resolute commitment. Endurance suggests the ability to withstand and persist in the face of difficulty or challenges. These synonyms for constancy all express the idea of dependability, reliability and longevity.