Revent

A word that is used when a person independently invent something new, while being oblivious to the fact that it has already been invented by someone else.

Person 1: "I just invented something new!"
Person 2: "Oh really? What is it?"
Person 1: *Says something that had already been created*
Person 2: "No, that already exists."
Person 1: "Well then I revent it"