Arrogance is the way a person acts when they have decided they matter more than you, and they let you feel it. It is not the same as being proud. Proud can be quiet and fair: you did the work, you know it, you do not need to step on anyone. Arrogance is the extra layer — talking down, not listening, taking up the room as if other people are in the way. You meet the word at school, at work, in politics. It is a blame-word. Nobody smiles and claims their own arrogance. Though actually people use it a little loosely. Someone who is only blunt, or tired, or sure because they are right, can still get called arrogant. The tidy meaning is “rude because you think you are very important.” Real talk sometimes just means “I did not like how sure they sounded.”