The Frontal Slit Defintion also known as "FSD" is the Gap between a females pussy lips common to that of a Camel Toe.
The Frontal Slit Definition on Stephanie was huge, it reminded me of a Camel toe or the gap between the slats in a picket fence. I was about to eat this bitches pussy & Her FSD was so large I heard an echo.!
by Anthony Minetti May 05, 2007