She promised to love him for all 'eternity'. [=to love him forever]
We suffered through an 'eternity' of delays during the lawsuit.
They believed that sinners would spend 'eternity' in hell.
(..) in the new order, second only to my own! I offer you a chance for greatness, Jor-El! Take it! Join us! You will bow down before me, Jor-El. I swear it! No matter that it takes an eternity! You will bow down before me! Both you and then one day... ...your heirs! Forgive me, forgive me.... (..)1978 Superman