The French with less than clean clothes (7)
I believe the answer is:
launder
'clean clothes' is the definition.
(I've seen this before)
'the french with less than' is the wordplay.
'the french' becomes 'la'.
'with' is a charade indicator (letters next to each other).
'less than' becomes 'under' (I've seen this before).
'la'+'under'='LAUNDER'
(Other definitions for launder that I've seen before include "Cleanse (material or money)" , "Perhaps decriminalise" , "Arundel (anag.)" , "Make clean, clothing or money" , "address the filth in lucre?" .)