Synonyms of eternal

Adjective

1. ageless, aeonian, eonian, eternal, everlasting, perpetual, unending, unceasing, permanent (vs. impermanent), lasting

usage: continuing forever or indefinitely; "the ageless themes of love and revenge"; "eternal truths"; "life everlasting"; "hell's perpetual fires"; "the unending bliss of heaven"

2. endless, eternal, interminable, long (vs. short)

usage: tiresomely long; seemingly without end; "endless debates"; "an endless conversation"; "the wait seemed eternal"; "eternal quarreling"; "an interminable sermon"

Definition and meaning of eternal (Dictionary)