nonsentence

A nonsentence is a sentence which makes no sense. Usually occurring during online chat, when one party is not paying attention to the other. A nonsentence rejects context and clarity and has no place in the conversation.

You: "You sure do love bagels, don't you?"
Them: "You know I have!"
You: "That was a nonsentence."
Them: "You're right. I'm sorry."
You: "Pancakes!"