The phrase "symbol of immortality" refers to a representation or sign that suggests an object or idea capable of lasting forever. When looking for synonyms for this phrase, certain words come to mind, such as eternal, unending, undying, ageless, and everlasting. Other synonyms that can be used for "symbol of immortality" include infinity, perpetuity, timelessness, endurance, and permanence. These words imply longevity and continuity that lasts beyond one's lifetime. Whichever synonym used, it conveys the idea of a powerful symbol that represents the concept of life without end.