1 infinite or unending (esp. future) time.
2 Theol. endless life after death.
3 the state of being eternal.
4 colloq. (often prec. by an) a very long time.
5 (in pl.) eternal truths.
Phrases and idioms:
eternity ring a finger-ring set with gems all round, usu. given as a token of lasting affection.
Etymology: ME f. OF eterniteacute f. L aeternitas -tatis f. aeternus: see ETERNAL
Useful english dictionary. 2012.