Coruscate (5)
I believe the answer is:
gleam
'coruscate' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for gleam that I've seen before include "Shine brightly" , "Faint light; (quality) shine (in eyes)" , "Glimmer, lustre" , "Brief bright light" , "Glow of light" .)