Brightly shining (7)
I believe the answer is:
radiant
'brightly shining' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for radiant that I've seen before include "Effulgent" , "'Glorious, shining (7)'" , "glowing with happiness" , "Very rich (7.2.2)" , "Very conspicuous" .)