That space under your knee; the scientific name is not known. Generally this area does not grow coarse hair unless you accidentially rub rogaine on it. If such a thing was done, you'd have a hairy knee-pit.
Girl 1-"Ohmygod, I was shaving my legs last night and cut my knee-pit! Now everytime I squat down more blood gushes out D:"
Girl 2-"Yoh at least your older brother didnt wipe rogaine all over it when you were sleeping, my brother did and now I have a hairy knee pit!"