Ranchers regularly playing cards (4)
I believe the answer is:
aces
'playing cards' is the definition.
(ace is a kind of playing card)
'ranchers regularly' is the wordplay.
'regularly' indicates alternate letters (regularly take one letter, leave next etc.).
The alternating letters of 'ranchers' are 'ACES'.
(Other definitions for aces that I've seen before include "Winning serves" , "Expert fliers" , "Top cards or people" , "Experts (in their field)" , "Two will make deuce" .)