aeonial
/iːˈəʊnɪəl/(also aionial, eonial)
adjective
Of or relating to an aeon; lasting an aeon; eternal, everlasting.
Origin
Early 19th century; earliest use found in Universalist's Miscellany. From ancient Greek αἰώνιος eternal (from αἰών + -ιος, suffix forming adjectives) + -al.