Remove from French channel (6)
I believe the answer is:
deduct
'remove' is the definition.
(I've seen this before)
'from french channel' is the wordplay.
'from french' becomes 'de' ('from' in French).
'channel' becomes 'duct' (synonyms).
'de'+'duct'='DEDUCT'
(Other definitions for deduct that I've seen before include "Remove" , "Withhold" , "Subtract, take away" , "Make a subtraction" , "Knock off" .)