Continuing infinitely or indefinitely.
Having existed for so great a period of time that its longevity cannot be expressed.
Always appearing youthful; never seeming to age.
Timeless; immortal
Without a date imprinted, assigned, or associated.
Out of one's head; deranged.
Thick-headed.
Having no date—a meeting with a lover or potential lover.
Without a start; immemorial