The word longeval means having a long lifespan. Some synonyms for longeval include long-lived, durable, immortal, ageless, and perennial. Long-lived refers to something or someone that has a long lifespan or has lived for a long time. Durable refers to something that is sturdy and long-lasting. Immortal means never dying or never-ending. Ageless refers to something or someone that does not age or looks timeless. Perennial means something that lasts year after year. These synonyms can be used interchangeably with the word longeval depending on the context.