Takes away from French channels (7)
I believe the answer is:
deducts
'takes away' is the definition.
(I've seen this before)
'from french channels' is the wordplay.
'from french' becomes 'de' ('from' in French).
'channels' becomes 'ducts' ('duct' can be a synonym of 'channel').
'de'+'ducts'='DEDUCTS'
(Other definitions for deducts that I've seen before include "Takes away" , "Subtracts" .)