A phrase or setence of which used that is not appropriate or not rellevant to a question or statement. The stupid response tends to be some thing undescribably odd to read or look at and alsi tends to come from someone who is also stupid. Could also come from someone who is not paying attention to the conversation.
This is a stupid response (person 2):
Person 1:Man my best friend just got hit by 2 cars. one took off and the other guy stayed and helped. But he has a dislocated leg, broken spine broken hip and road rash.
Person 2:lol, nice :D or Awesome!XD