Grease smeared on greyish brown garment (9)
I believe the answer is:
dungarees
'garment' is the definition.
(dungarees are a type of item of clothing)
'grease smeared on greyish brown' is the wordplay.
'smeared' is an anagram indicator.
'on' means one lot of letters goes inside another (as in clothing 'on' a person).
'greyish brown' becomes 'dun' (synonyms).
'grease' anagrammed gives 'garees'.
'garees' placed around 'dun' is 'DUNGAREES'.
(Other definitions for dungarees that I've seen before include "Work overalls" , "Overalls of cotton fabric" , "Overall" , "garment" , "protection at work" .)