Garment waste a wise man rejected (9)
I believe the answer is:
dungarees
'garment' is the definition.
(dungarees are a type of item of clothing)
'waste a wise man rejected' is the wordplay.
'waste' becomes 'dung' (dung is a kind of waste).
'wise man' becomes 'seer' (I've seen this in another clue).
'rejected' shows that the letters should be reversed in order.
'seer' in reverse letter order is 'rees'.
'dung'+'a'+'rees'='DUNGAREES'
(Other definitions for dungarees that I've seen before include "garment" , "Worker's trousers with a bib" , "Overall" , "Hard-wearing work trousers with a bib" , "protection at work" .)