Regularly urge stringent limit (8)
I believe the answer is:
restrict
'limit' is the definition.
(restricting is a kind of limiting)
'regularly urge stringent' is the wordplay.
'regularly' indicates alternate letters (regularly take one letter, leave next etc.).
'stringent' becomes 'strict' (I've seen this before).
The alternate letters of 'urge' are 're'.
're'+'strict'='RESTRICT'
(Other definitions for restrict that I've seen before include "'Restrain, limit (8)'" , "Circumscribe" , "Limit, inhibit" , "Check" , "Limit or regulate" .)