Ray's broad smile (4)
I believe the answer is:
beam
This clue is a double definition.
'ray's' is the first definition.
(synonyms)
'broad smile' is the second definition.
(I've seen this before)
(Other definitions for beam that I've seen before include "Smile brightly - supporting timber" , "Radiant smile; timber support" , "Perhaps a summer" , "Smile, light shaft" , "Gymnast's bar; broad smile" .)