A worthless peice of shit who is so repulsive and generally nasty, that calling him a mere asshole simply isnt enough. Thus the word Cunthole was created.
Here is a prime example of a cunthole.
Danny: Hey guys, last night i got a girl incredibly drunk, and then i took advantage of her. I didnt use a condom either, and i gave her clamidia. HAHAHAHAHA
Carl: Danny that was just wrong, why would you do that? You are such a fucking cunthole
Someone who acts as a friend, but really is gathering information to:
a) use against you
b)to use out of context or
c)to twist into something completely false.