look up any word, like dirty sanchez:
 
1.
Something that is so disgustingly hideous it is comparable to sin itself, not necessarily physically ugly, something so disturbingly ugly it makes your stomach churn.
1. The old renault Twingo is as ugly as sin.

2. Jesus Christ that girl is as ugly as sin.
by Arthur C September 16, 2007
 
2.
a human so repulsive they are either laughable, or just generally disgusting.
"look at her, you wouldnt touch her with a bargepole, shes ugly as sin!"
by DawnHoneybees January 24, 2008
 
3.
the ugliest fucking chick uve ever seen on this whole planet....so ugly it is a sin to be so hideous
"man check out that chick she is ugly as sin i thinka im gon throw up!!"
by uhhhMARISSA September 21, 2005