self-importantadjective
self-importantlyadverb
self-importance | American Dictionary
self-importance
noun[ U ]
us/ˌself·ɪmˈpɔrt·əns/
the belief that you are more important or valuable than other people:
He strutted into the room, self-importance written all over his face.
self-important
adjectiveus/ˌself·ɪmˈpɔrt·ənt/
You are a self-important little twerp.