Ray gives smile (4)
I believe the answer is:
beam
This clue is a double definition.
'ray' is the first definition.
(I know that ray can be written as beam)
'smile' is the second definition.
(to beam is to smile)
'gives' is the link.
(Other definitions for beam that I've seen before include "Smile brightly - supporting timber" , "Shine" , "Radiant smile; timber support" , "Ray; piece of timber" , "Smile, light shaft" .)