Smile at supporter (4)
I believe the answer is:
beam
This clue might be a double definition.
'smile' is the first definition.
(to beam is to smile)
'supporter' is the second definition.
Although both the answer and definition are singular nouns, I cannot see how one could define the other.
'at' is the link.
Can you help me to learn more?
(Other definitions for beam that I've seen before include "Rafter - smile - width" , "Supporting piece of wood - shaft of light" , "Wide grin" , "Smile, transmit (radio signal)" , "A broad smile like lunar ray" .)