Pompous

Pompous (sometimes spelled pompus) applies to a person who believes they are on top of everything and successful. The definition of pompous is, characterized by excessive self-esteem or exaggerated dignity, in other words...being pretentious. The behavior is usually acting posh and self-centered, like a jerk.

Pompous can also refer to being bombastic, using a lot of big words.

The etymology of pompous is from Middle English; in turn from Old French, pompeux; which came from Late Latin, pompsus; and starting from Latin, pompa.