look up any word, like fap:
 
1.
The process of being penetrated in the booty hole while giving birth.
Christopher is a firth baby.
by CupDude February 17, 2009
 
2.
A derivative of filth. Meaning lower than specks of dust on your shoes.
Man, that is pure firth!
by Crismon June 16, 2003
 
3.
Puss-filled bubble, usually located around the anus.
"Yo, is that Firth in that Chevy?"
by Dr. Curtis December 06, 2003
 
4.
a bacterial disease
skinny white boy who looks like he has down syndrome = firth
by sam excellent December 04, 2003