Civil years are often used to refer to the number of years that have passed since someone was born, and are typically based on the Gregorian calendar. However, there are several other terms that can be used to refer to the same concept. One common synonym is "calendar years," which simply refers to the number of years since a particular date. Another similar term is "chronological years," which emphasizes the sequential nature of time as it passes. Other potential synonyms for civil years include "life years," "age," and simply "years." Regardless of the term used, tracking the passage of time is an important part of human experience.