Mock fool carrying amplifier (7)
I believe the answer is:
lampoon
'mock' is the definition.
(I've seen this before)
'fool carrying amplifier' is the wordplay.
'fool' becomes 'loon' (I've seen this before).
'carrying' means one lot of letters goes inside another.
'amplifier' becomes 'amp' (abbreviation).
'loon' placed around 'amp' is 'LAMPOON'.
(Other definitions for lampoon that I've seen before include "Written ridicule of polo man" , "Pool man (anag)" , "Make fun of" , "Parody" , "ridiculous scenario" .)