deathless

adjective2

1. •
   Undying or immortal.

   • Athena For mighty is the potency of the revered Erinyes both with the deathless high gods and with the powers of the world below; […] — 1926
2. •
   Guaranteed not to be lost or forgotten due to its importance or conspicuous excellence.

   • Her novels are filled with unforgettable characters and deathless prose.