(a.) Not capable of being extinguished; extinguishable; unquenchable; as, inextinguishable flame, light, thirst, desire, feuds.

deathless enduring eternal everlasting immortal imperishable impregnable incorruptible indelible indestructible ineffaceable ineradicable inexpugnable invincible invulnerable irrefragable irrepressible nonperishable quenchless undampable undestroyable undying unquenchable