Have you ever been to an event and met Joe Obnoxious? You cannot mistake him for anyone else. Joe comes up to you and just starts talking about what he does, how well he does it, and how you should do it with him.
Or what about Joanna Obnoxious, who starts talking to you and, while talking. she is looking all over the room to see who else is there, who might be more important than you. Then just after she asks you what you do, she excuses herself and takes off to see someone else.
The word that comes to mind is “obnoxious.”
The action that comes to mind is, “How can I stay away from this person and how can I keep her/him away from my friends?”
One of the biggest keys to success in speaking with people is listening and letting the other person talk. Ask questions, never assume you know anything. You saw these two people above, they did not follow any of these rules, nor did they understand the principles. They did not understand, “he who asks the questions controls the conversation.”
When you run into Mr. and Ms. Obnoxious, you simply say to them, “sorry but I have to go.” Then move away from them. Don’t worry about what they might think. By the time you get 10 feet away, they will already have found someone else to annoy.