Smiles at rays (5)
I believe the answer is:
beams
This clue is a double definition.
'smiles' is the first definition.
(beaming is a kind of smiling)
'rays' is the second definition.
(I have seen 'Rays of light ' mean 'beams' so perhaps 'rays' could also mean 'beams')
'at' is the link.
(Other definitions for beams that I've seen before include "Smiles; joists" , "Smiles broadly or sunnily" , "Shines" , "Rays of light" .)