Glare (6)
'glare' is the definition.
(synonyms)
This is the entire clue.
(Other definitions for glower that I've seen before include "Not a good look" , "Threatening look" , "firefly?" , "Fierce look" , "Look black" .)
(Other definitions for dazzle that I've seen before include "Overcome with intense light" , "Blind with light or brilliance" , "Temporarily blind with bright light" , "Blind with light or skill" , "Animal's den" .)