Robin, perhaps, returning prize to king (4)
I believe the answer is:
puck
'robin' is the definition.
(Shakespeare character Puck or Robin Goodfellow)
'returning prize to king' is the wordplay.
'returning' says the letters should be written in reverse.
'prize' becomes 'cup' (cup is a kind of prize).
'to king' becomes 'K' (abbreviation for king in chess).
'cup' in reverse letter order is 'puc'.
'puc'+'k'='PUCK'
'perhaps' is the link.
(Other definitions for puck that I've seen before include "Mischievous sprite, Robin Goodfellow (AMND)" , "In plentiful supply" , "Oberon's sprite (AMND)" , "gets knocked about with sticks" , "Mischievous spirit" .)