Part of film dealing with the Spanish dance (4)
I believe the answer is:
reel
'part of film' is the definition.
(as in a reel of film)
'dealing with the spanish dance' is the wordplay.
'dealing with' becomes 're' (regarding).
'the spanish dance' becomes 'el' (I can't justify this - if you can you should give a lot more credence to this answer).
're'+'el'='REEL'
(Other definitions for reel that I've seen before include "Wind" , "Stagger with rod winder" , "Dance; winding cylinder" , "Lively Scottish dance" , "Photographer's and anglers spool" .)