ageless
— Adjective
– English
~ continuing forever or indefinitely; "the ageless themes of love and revenge"; "eternal truths"; "life everlasting"; "hell's perpetual fires"; "the unending bliss of heaven"
agelessness
— Noun
– English
~ the quality of being timeless and eternal
agelong
— Adjective
– English
~ lasting through all time; "agelong struggle for freedom"