Peer of the realm (5)
I believe the answer is:
noble
'peer of the realm' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for noble that I've seen before include "gold coin, now obsolete" , "like Basie or Ellington?" , "Illustrious - of high birth - old gold coin" , "Magnificent old coin" , "fine" .)