Noun - Someone who is being an asshole at the spur of the moment. It is a contraction of "Bitch" and "Dick" (Bitch + Dick = Bacock)
Verb - Sarah Jessica Parker just bacocked some homeless guy! Did you hear him squawk?
Noun - Wow, way to say a vagina joke infront of Megan Fox right while I was about to hook up with her you bacock!