Pretension is what you're guilty of when you boorishly try to impress other people with how important or clever you are.
When you speak with pretension, you're boastful and you puff yourself up as someone very important or of great worth. If you have literary pretentions, you mostly likely think you're a great writer, but you most likely are not. As you might imagine, this word has the same Latin roots as pretend and pretense. A pretension can also be the advancing of a claim.