He may lightly be addressed as –Sunshine” (3)
I believe the answer is:
ray
'he' is the definition.
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for ray that I've seen before include "bit of sunshine" , "Beam or flatfish" , "Man who engaged in surrealist photography" , "Gleam" , "Flat fish or sun beam" .)