deathless (adj.)

• abiding
• amaranthine
• eternal
• everlasting
• frozen
• immortal
• imperishable
• impregnable
• incorruptible
• indelible
• indestructible
• ineradicable
• inexpugnable
• inextinguishable
• invincible
• invulnerable
• lasting
• never-ending
• permanent
• persisting
• quenchless
• timeless
• undestroyable
• undying
• unending
• unfading
• unquenchable