2. A stupid individual, a dolt, a dumbass motherfucker
n2: An insult used to chastise someone who's behavior is annoying you and/or others. The insult infers that the person inflicting the annoyance on you and/or others is becoming as irritating as an unpleasant and unwanted experience of anal penetration.
Example for n2: "Hey! Cut that out. You're such a butt plug!"