A very superior glare, possibly (5)
I believe the answer is:
regal
'a very superior' is the definition.
Both the answer and definition are adjectives. Perhaps you can see a link between them that I don't see?
'glare possibly' is the wordplay.
'possibly' indicates anagramming the letters.
'glare' is an anagram of 'REGAL'.
Can you help me to learn more?
(Other definitions for regal that I've seen before include "Fit for a monarch" , "King-like" , "Portable organ" , "Showing great dignity" , "Kingly or queenly" .)