Noble god, over time, displaying eternal youth (5,3)
I believe the answer is:
peter pan
'eternal youth' is the definition.
'noble god over time' is the wordplay.
'noble' becomes 'peer' (peers are members of the nobility).
'god' becomes 'Pan' (Pan is a Greek god).
'over' indicates putting letters inside.
'time' becomes 't' (abbreviation).
'peer'+'pan'='peerpan'
'peerpan' enclosing 't' is 'PETER PAN'.
'displaying' acts as a link.
(Other definitions for peter pan that I've seen before include "J M Barrie's immortal boy" , "J M Barrie's ever-young boy" , "Ever-youthful boy" , "J M Barrie's boy who never grew up" , "voyager to Never Never Land" .)