Noun. A person who is genuinely retarded and serves no positive purpose to society. See also dickhead.
After watching Ken Hitchcock say the Flyers lost because their team is not good enough, Steve Coates reported that Ken Hitchcock was formally protesting the game because the refs blew it for the Flyers. I screamed, "That's not what he said you dickhead." But Steve Coates was just being a Coatesy. For examples of this in actions, watch "Coatesy's Corner."
Adj. To be stupid to the point of mental retardation, while making absolutely no sense at all.
Bob was watching the Flyers' game when Roenick took a cheap shot on someone and Bob screamed that there should have been a penalty for interfering with Roenick. I responded by telling him his statement was a Coatesy remark and I thus bitch-slapped him upside the head and told him to get me a case of two-four.