Boaster (8)
I believe the answer is:
braggart
'boaster' is the definition.
(I know that boaster can be written as braggart)
This is the entire clue.
(Other definitions for braggart that I've seen before include "Show-off" , "self-publicist" , "One who boasts loudly" , "Big boaster" , "Boastful type" .)