Become a father, returning in derision (4)
I believe the answer is:
sire
'become a father' is the definition.
(I've seen this in another clue)
'returning in derision' is the wordplay.
'returning' shows that the letters should be reversed in order.
'in' indicates a hidden word.
'eris' is hidden in the letters of 'derision'.
'eris' written backwards gives 'SIRE'.
(Other definitions for sire that I've seen before include "Bear" , "Stallion; beget" , "Make children" , "Male parent of an animal" , "Generator" .)