without beginning or end; lasting forever; always existing ( opposed to temporal )

eternal life.

perpetual; ceaseless; endless

eternal quarreling; eternal chatter.

enduring; immutable

eternal principles.

Metaphysics . existing outside all relations of time; not subject to change.

something that is eternal.

the Eternal, God.

adjective

brief , changeable , changing , ending , ephemeral , stopping , temporary , terminable , transient

adjective

abiding , ageless , always , amaranthine , boundless , ceaseless , constant , continual , continued , continuous , dateless , deathless , enduring , everlasting , forever , illimitable , immemorial , immortal , immutable , imperishable , incessant , indefinite , indestructible , infinite , interminable , lasting , never-ending , perdurable , perennial , permanent , perpetual , persistent , relentless , termless , timeless , unbroken , unceasing , undying , unending , unfading , uninterrupted , unremitting , without end , sempiternal , around-the-clock , endless , nonstop , ongoing , round-the-clock , unfailing , world without end , ab aeterno , asonian. seeeverlasting , changeless , diuturnal , in aeternum , indefectible , self-existent , supertemporal