Make a choice and compete regularly (3)
I believe the answer is:
opt
'make a choice' is the definition.
(I've seen this before)
'compete regularly' is the wordplay.
'regularly' indicates alternate letters (regularly take one letter, leave next etc.).
The alternating letters of 'compete' are 'OPT'.
'and' is the link.
(Other definitions for opt that I've seen before include "Elect" , "Prefer, choose" , "End or act of shutting" , "Plump for" , "Hold in the highest esteem" .)