A derivative of filth. Meaning lower than specks of dust on your shoes.
Man, that is pure firth!
di Crismon 16 giugno 2003
The process of being penetrated in the booty hole while giving birth.
Christopher is a firth baby.
di CupDude 17 febbraio 2009
Puss-filled bubble, usually located around the anus.
"Yo, is that Firth in that Chevy?"
di Dr. Curtis 06 dicembre 2003