something that kills the conversation because of its randomness or weirdness. Usually said after the awkward comment was used with "that was" before it. Also a certain expression is amde with the face of the person saying tooner by opening his/her eyes as wide as possible and lifting eyebrows. Many times a person doesn't even have to say tooner and will only say "That was" and imply it.
person 1: I'm gona wear my super tight shirt so that everyone will think I'm buff.
person 2:That was tooner/ you are tooner/ That WAS!