Regularly stroke piggy (3)
I believe the answer is:
toe
'piggy' is the definition.
(I've seen this in another clue)
'regularly stroke' is the wordplay.
'regularly' indicates alternate letters (regularly take one letter, leave next etc.).
The alternate letters of 'stroke' are 'TOE'.
(Other definitions for toe that I've seen before include "Pedal extremity" , "Pedal digit" , "Part of foot" , "Extremity of the body" , "Calabria?" .)