bumptious
Annoyingly bossy and full of themselves.
Bumptious means annoyingly self-important and pushy. A bumptious person acts like they're more important than everyone else and isn't shy about showing it. They might interrupt conversations to share their opinions, brag constantly about their accomplishments, or boss people around even when no one asked them to be in charge.
Picture a classmate who always has to be first in line, brags about every good grade, and tells everyone else how to do things the “right way” (meaning their way). That's bumptious behavior. The word captures obnoxious, intrusive overconfidence that makes others uncomfortable.
A bumptious person might push their way into a group project and immediately start giving orders, or interrupt a teacher to explain something “better.” They lack the self-awareness to notice that their pushiness is bothering people. While confidence means believing in yourself, being bumptious means believing you're better than others and making sure everyone knows it.