Mocking English father in short film falling over (8)
I believe the answer is:
derisive
'mocking' is the definition.
('derisive' can be a synonym of 'mocking')
'english father in short film falling over' is the wordplay.
'english' becomes 'e' (abbreviation).
'father' becomes 'sire' ('sire' can be a synonym of 'father').
'in' means one lot of letters goes inside another.
'short film falling' becomes 'vid' (I can't explain this - if you can you should believe this answer much more).
'over' says the letters should be written in reverse.
'sire' put inside 'vid' is 'visired'.
'e'+'visired'='evisired'
'evisired' backwards is 'DERISIVE'.
Can you help me to learn more?
(Other definitions for derisive that I've seen before include "Contemptuous" , "Taunting" , "Expressing contempt" , "'Scornful, mocking (8)'" .)