Middle part of classic family film (4)
I believe the answer is:
skin
'film' is the definition.
(I've seen this in other clues)
'middle part of classic family' is the wordplay.
'middle part of classic' becomes 's' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'family' becomes 'kin' ('kin' can be a synonym of 'family').
's'+'kin'='SKIN'
Can you help me to learn more?
(Other definitions for skin that I've seen before include "Outer covering" , "Remove the outer layer" , "Protective body covering" , "Peel; drum head" , "Surface layer" .)