Shine softly (4)
I believe the answer is:
glow
'shine softly' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for glow that I've seen before include "Shine, maybe in dark" , "rosy colour" , "Shine with warmth, emotion" , "Burn without flame" , "Redness of the cheeks" .)