A derivative of filth. Meaning lower than specks of dust on your shoes.
Man, that is pure firth!
af Crismon 16. juni 2003
The process of being penetrated in the booty hole while giving birth.
Christopher is a firth baby.
af CupDude 17. februar 2009
Puss-filled bubble, usually located around the anus.
"Yo, is that Firth in that Chevy?"
af Dr. Curtis 6. december 2003