Aureole (6)
I believe the answer is:
corona
'aureole' is the definition.
(synonyms)
This is the entire clue.
(Other definitions for corona that I've seen before include "Big Smoke" , "Glow around conductor" , "It's visible as a halo during a solar eclipse" , "Circle of light around the sun during an eclipse" , "Glow around the sun" .)