Rare quality defining peer (5)
I believe the answer is:
equal
'peer' is the definition.
(synonyms)
'rare quality defining' is the wordplay.
'EQUAL' is hidden within the letters.
However, I am unsure how the hidden word is indicated.
Can you help me to learn more?
(Other definitions for equal that I've seen before include "Match; evenly balanced" , "The same in size, amount or value, etc." , "The same; even" , "Evenly-matched" , "Fifty-fifty" .)