Boastful person is to get bashed (7)
I believe the answer is:
egotist
'boastful person' is the definition.
(I've seen this before)
'is to get bashed' is the wordplay.
'bashed' indicates an anagram.
'is'+'to'+'get'='istoget'
'istoget' with letters rearranged gives 'EGOTIST'.
(Other definitions for egotist that I've seen before include "Boastful person" , "Person with inflated self-image" , "show-off" , "Bighead" , "braggart" .)