The amount of space in between the woman's vagina where you can feel her walls. If you can feel her walls very well then she has lots of tread. If you can't feel her then she has no tread left. There is a tread scale.
5 - Virgin
4 - She's not a whore
3 - Maybe been around here and there
2 - You're definitely not her first
1 - You better be big
0 - Hot dog down the hallway
Emily has lots of tread, she was right about not being a hoe.
Bernice: "I have lots of tread and I have slept around a bunch."