braggart

noun braggart

• know-it-all — a person who acts as though he or she knows everything and who dismisses the opinions, comments, or suggestions of others.
• windbag — Informal. an empty, voluble, pretentious talker.
• boaster — a chisel for boasting stone.
• blowhard — If you describe someone as a blowhard, you mean that they express their opinions very forcefully, and usually in a boastful way.
• brag — If you brag, you say in a very proud way that you have something or have done something.