Someone who is not normal and constantly trolling you with pranks and just overall annoying. It is usually used as gamer slang and created by a group of teens who tried to say co-owner but aggressively changed it as an insult. Also used in a roast battle to stun your opponent. Goes in with the saying "madcone".
Jimmy tried to start a flame battle, so a brought up the game I beat him in. He turned around and called me a Conowner and the crowd went silent. He walked away proud.
Boys who enjoy yaoi (a genre in Japan that contains sexual and/or romantic relations between two men); literally translates to "rotten boy"; corresponding female : fujoshi