Uncommon Elgar variation (5)
I believe the answer is:
regal
'uncommon' is the definition.
Both the answer and definition are adjectives. Maybe they are linked in a way I don't understand?
'elgar variation' is the wordplay.
'variation' indicates anagramming the letters.
'elgar' with letters rearranged gives 'REGAL'.
Can you help me to learn more?
(Other definitions for regal that I've seen before include "Royal - 5 down (anag)" , "Magnificent, dignified" , "befitting a king" , "Kingly or queenly" , "Befitting a monarch" .)