Bragged about scrap (3)
I believe the answer is:
rag
'scrap' is the definition.
(both can mean a piece of material)
'bragged about' is the wordplay.
'about' indicates the answer is hidden within the clue (the clue goes around or about the answer).
'RAG' is hidden in the letters of 'bragged'.
(Other definitions for rag that I've seen before include "Practical joke" , "Tatter; make fun of" , "Waste scrap of cloth" , "Scrap -student carnival" , "Bit of material" .)