Rook and pigs crossing dale regularly (7)
I believe the answer is:
swindle
'rook' is the definition.
(I know that rook can be written as swindle)
'pigs crossing dale regularly' is the wordplay.
'pigs' becomes 'swine' (I've seen this before).
'crossing' is an insertion indicator (to cross can mean to go over or around).
'regularly' means one should take alternating letters (regularly take one letter, leave next etc.).
The alternating letters of 'dale' are 'dl'.
'swine' enclosing 'dl' is 'SWINDLE'.
'and' acts as a link.
(Other definitions for swindle that I've seen before include "Scam" , "Cheat; fraud" , "Take" , "fleece" , "Rip off" .)