Rascal active politician stops to ridicule (7)
I believe the answer is:
lampoon
'ridicule' is the definition.
(lampooning is a kind of ridiculing)
'rascal active politician stops' is the wordplay.
'rascal' becomes 'loon'.
'active' becomes 'a' (grammatical abbreviation).
'politician' becomes 'mp'.
'stops' is an insertion indicator (to stop can mean to block a gap).
'a'+'mp'='amp'
'loon' going around 'amp' is 'LAMPOON'.
'to' acts as a link.
(Other definitions for lampoon that I've seen before include "Parody" , "send-up" , "Satirical work" , "Pool man (anag)" , "Make fun of" .)