Film announced some century breaks (4)
I believe the answer is:
scum
'film' is the definition.
(I know that scum is a type of film)
'announced some century breaks' is the wordplay.
'announced' shows a homophone (sound like).
'century' becomes 'C' (common abbreviation).
'breaks' is an anagram indicator.
'some' is a homophone of 'sum'.
'sum'+'c'='sumc'
'sumc' is an anagram of 'SCUM'.
(Other definitions for scum that I've seen before include "Floating impurity layer" , "Floating impurities or worthless people" , "Dregs (of society?)" , "Floating dirt or froth" , "Dirty froth" .)