Clever at shining? (6)
I believe the answer is:
bright
I believe this clue is a double definition.
'clever' is the first definition.
(bright can mean clever or gifted)
'shining?' is the second definition.
(similar in meaning)
'at' acts as a link.
(Other definitions for bright that I've seen before include "Lustrous, shining" , "Effulgent" , "Clever - dazzling" , "Jolly" , "Cheerful or quick-witted" .)