A derivative of filth. Meaning lower than specks of dust on your shoes.
Man, that is pure firth!
by Crismon June 16, 2003
Can you define these popular missing words?
The process of being penetrated in the booty hole while giving birth.
Christopher is a firth baby.
by CupDude February 17, 2009
Puss-filled bubble, usually located around the anus.
"Yo, is that Firth in that Chevy?"
by Dr. Curtis December 06, 2003