eternal
Pronunciation: /ɪˈtəːn(ə)l, iː-/
adjective
- 1lasting or existing forever; without end: the secret of eternal youth fear of eternal damnation
- (of truths, values, or questions) valid for all time; essentially unchanging: eternal truths of art and life
- informal seeming to last or persist forever, especially on account of being tedious or annoying: eternal nagging demands she is an eternal optimist

Phrases
-
the Eternal City
- a name for the city of Rome.
-
eternal life
- Christian Theology spiritual existence after death of the body: the belief in eternal life
-
eternal triangle
- see triangle (sense 2).

Origin:
late Middle English: via Old French from late Latin aeternalis, from Latin aeternus, from aevum 'age'