Taking off top, show off scruffy garment (3)
I believe the answer is:
rag
'scruffy garment' is the definition.
(scruffy material)
'taking off top show off' is the wordplay.
'taking off top' means to remove the first letter.
'show off' becomes 'brag' (both can mean to boast about something).
'brag' with its initial letter removed is 'RAG'.
(Other definitions for rag that I've seen before include "Tease" , "Mock < paper that's poor" , "Tatter; make fun of" , "Duster, perhaps" , "This trade is the clothing business" .)