Timeless, eternal (7)
I believe the answer is:
ageless
I believe this is a double definition.
'timeless' is the first definition.
(synonyms)
'eternal' is the second definition.
(synonyms)
(Other definitions for ageless that I've seen before include "Ever youthful" , "Classic" , "impossible to date" , "Perpetually young" , "Never growing old" .)