Origin: 1350–1400; ME < LL
aeternālis, equiv. to
aetern(
us) (
see eterne ) +
-ālis -al 1 
Related forms: e⋅ter⋅nal⋅ly, adverb
Synonyms:
1. permanent, unending. Eternal, endless, everlasting, perpetual imply lasting or going on without ceasing. That which is eternal is, by its nature, without beginning or end: God, the eternal Father. That which is endless never stops but goes on continuously as if in a circle: an endless succession of years. That which is everlasting will endure through all future time: a promise of everlasting life. Perpeptual implies continuous renewal as far into the future as one can foresee: perpetual strife between nations. 3. timeless, immortal, deathless, undying, imperishable, indestructible.
Antonyms:
1. transitory. 3. mutable.