The rascal starts scoffing at a politician (5)
I believe the answer is:
scamp
'the rascal' is the definition.
(synonyms)
'starts scoffing at a politician' is the wordplay.
'starts scoffing' becomes 'sc' (I am not sure about this - if you are sure you should believe this answer much more).
'at' is a charade indicator (letters next to each other).
'politician' becomes 'MP' (Member of Parliament).
'sc'+'a'+'mp'='SCAMP'
Can you help me to learn more?
(Other definitions for scamp that I've seen before include "Scoundrel" , "pickle" , "A young rascal misbehaving in camps" , "Troublemaker" , "Rogue - perform inadequately" .)