A really wet fart, so wet you might need a change of underwear. Normally has a slime like texture. Can be found in most older folks soiled undergarments.
"Grandpa left a little fart sauce in there for you."
When two people fart and the smells combine to form a new and powerful stench.
Caitlyn and Darin sat in the car and farted from some nasty Mexican food and the car reaked of fartsauce!
1. often used as an insult for someone who is dimwitted.
2. greasy debris left from a particularly moist or raunchy fart.
1. shut your face, fart sauce!
2. I think that last one left behind a little fart sauce. That's gonna itch when it dries.