ageless

/EY1 JH L AH0 S/
adjective
  1. 1

    (relative to past) Having existed for so great a period of time that its longevity cannot be expressed.

    โ€œThe ageless pyramids stood prominently against the sunset.โ€

  2. 2

    (relative to future) Continuing infinitely or indefinitely.

    โ€œThis memorial will show our ageless respect to those who died.โ€

  3. 3

    Always appearing youthful; never seeming to age.

    โ€œHer ageless face.โ€

Source: https://en.wiktionary.org/wiki/ageless