Agerasia is a term used to denote the concept of eternal youth. It is derived from the Greek words 'age', which means 'not growing old' and 'rasia', which means 'old age'. While there are no exact synonyms for agerasia, there are several related words that indicate a similar idea. Terms like 'immortality', 'perennial youth', 'never aging' and 'timeless youth' all evoke the idea of eternal youth and vigor. Other words like 'vitality', 'vigor', 'liveliness' and 'energy' also touch on the concept of youthfulness and vigor. In general, agerasia and its synonyms all connote the state of being youthful, vibrant and full of life, regardless of one's age.