aeonian

adjective

ae·​o·​ni·​an ē-ˈō-nē-ən 

variants or aeonic

ē-ˈä-nik 

: lasting for an immeasurably or indefinitely long period of time

… the whole universe is a realm of aeonian conflicts, slow and mighty …

—Gilbert Highet

Word History

Etymology

aeonian, from Greek aiṓnios "lasting an age, perpetual" (derivative of aiṓn eon) + -an entry 2; aeonic from eon + -ic entry 1

First Known Use

1761, in the meaning defined above