Collie of film (6)
I believe the answer is:
lassie
'collie of film' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for lassie that I've seen before include "Scottish girl - canine movie star" , "Canine film star" , "Young Scottish girl or Hollywood lost dog" , "Film and TV dog" , "Collie featuring in many films" .)