Forever
Eternity, Permanence
noun, な adjective, の adjective
えいえん
永遠 (えいえん、fake) Forever, Eternity, Permanence
永久 (えいきゅう) Forever, Eternity
悠久 (ゆうきゅう) Eternity, Perpetuity, Permanence
This is the Eternity えい that actually ends えん in like a day or two.