Char piece of chicken with less fat (7)
I believe the answer is:
cleaner
'char' is the definition.
(old-fashioned term for a cleaner)
'piece of chicken with less fat' is the wordplay.
'piece of' suggests taking the first letters.
'with less fat' becomes 'leaner' (lean means not having much fat).
The initial letter of 'chicken' is 'c'.
'c'+'leaner'='CLEANER'
(Other definitions for cleaner that I've seen before include "More sanitary" , "Less soiled" , "less sleazy?" , "One who dusts or vacuums" , "Chemical agent for removing dirt" .)