braggart

nouns

a very boastful and talkative person
blowhard, boaster, braggart, bragger, line-shooter, vaunter
is derived from
brag

adjectives

exhibiting self-importance
"big talk"
big, boastful, braggart, bragging, braggy, cock-a-hoop, crowing, self-aggrandising, self-aggrandizing