A person who thinks he is awesome, but everyone really only tolerates his presence to have someone to poke fun at.

A person (typically male) who refuses to engage in normal romantic relationships. They are sometimes referred to as "emotionally unavailable" and tend to lie, cheat and manipulate women until the woman is whipped into a state of complete confusion and suicidal tendencies. Often times the unsuspecting female is initially lured by very romantic, passionate, hot behavior only to be met with ice once she starts to expect some of the lies the assclown has dished out.

someone who acts like an idiot to the fullest.

a man who overestimates his importance in anyones life, has left a mark on society in the form of a stain on its undergarments and often goes by geeky names like "grax" in chat rooms

One that is a complete mistake to existence, and absolutely terrible at everything they do.

a fool or idiot

Noun:

1. A troll who frequents the same chat room/game room with the express intent to annoy the regulars with ilk, foul language and total disgust and rudeness. Usually said assclown will end up getting the perma-mute by everyone.

2. In general, on the society totem pole, someone who is lower than an asshole or jack ass.