A girl you who add's you on myspace. Then you look at her pictures and she has a fucked up grill and is wearing red lipstick looking like a transvestite and shit, she also has a fat cunt of a mole on her face
I was at a night club and a horse faced slut approached me and grinding against me when the new 50 track came on, it was gangsta rap and a horse faced slut, I ran home
a word that is given to a lot of people or celebs just simply as an exaggeration, because someone has a slightly long or evan oval shaped face/big teeth/buck teeth/gummy teeth or a goofy smile (probably about half the population then) loads of celebs out there from eva longoria to christina aguilera, prince william or leona lewis have been called a horse. i don't think they are considered ugly to most people, nor are horses themselves.
When you fail at something in life (eg. failing an exam or not getting a job), go home and spend an hour just standing in the shower, propping yourself up against the wall with your eyes on your feet.
Caleb knew the only thing to do after he didnt get prefect was take a failureshower.