Broad smile seen in skating rink (4)
I believe the answer is:
grin
'broad smile' is the definition.
(I've seen this before)
'in skating rink' is the wordplay.
'in' indicates the answer is hidden within the clue.
'GRIN' is hidden in the letters of 'skating rink'.
'seen' acts as a link.
(Other definitions for grin that I've seen before include "Smile broadly showing teeth" , "Cheesy smile?" , "Beam" , "Smile - all that could be seen of the vanishing Cheshire Cat" , "A broad smile showing the teeth" .)