Unprepared commercial for a politician (5)
I believe the answer is:
adlib
'unprepared' is the definition.
I know nothing about this answer so I can't judge whether this works.
'commercial for a politician' is the wordplay.
'commercial' becomes 'ad' (abbreviation for advertisement).
'for' says to put letters next to each other.
'a politician' becomes 'lib' ().
'ad'+'lib'='ADLIB'
Can you help me to learn more?
(Other definitions for adlib that I've seen before include "wing it" , "not prepared for speech" .)