Glint or flare (5)
I believe the answer is:
spark
This clue is a double definition.
'glint' is the first definition.
(I know that glint can be written as spark)
'flare' is the second definition.
(thesaurus)
(Other definitions for spark that I've seen before include "Fragment of a burning substance" , "Electrical discharge" , "Fiery particle" , "Flicker -- provoke" , "Particle of fire" .)