Regularly pursue advantage (3)
I believe the answer is:
use
'advantage' is the definition.
(I've seen this in another clue)
'regularly pursue' is the wordplay.
'regularly' means one should take alternating letters (regularly take one letter, leave next etc.).
The alternate letters of 'pursue' are 'USE'.
(Other definitions for use that I've seen before include "Employ or exploit" , "Exploit; custom" , "Profit" , "Benefit" , "Employ, put into service" .)