A person who has little intelligence and who constantly gets on people's nerves of no apparent reason. Typically cares about no one else and is overly confident. Downplays and ridicules others that are superior to himself/herself.
Karen is such a douchebag. She thinks and acts like she's better than Joanthan even though in real life, Jonathan is better and smarter than Karen. Not to mention, her face smells like one too.