This word can mean anything that you want.
Best used when memory loss has occured or when there are people around that wouldn't appreciate the word that it is intended to be.
"Look at the furtle durtle on that!"
In this case furtle durtle means VW beetle bonnet on a Lady in extremely tight pants in a crowded drinking establishment.
This expression arose around 2008 no Brazil due to a song called Furfles Fellings in a program of MTV Brazil. Its creator Marcelo Adnet claims that the expression arose due to a joke that non-English speaking people wind up meaningless words when they sing their favorite songs. The term Furfles can be a derivation of Furf + Less that we can understand as Man of Truth + Less. So Furfles means: "Less real man." - search youtube (furfles mtv)