knee whiskers
the hairs around your knees you always seem to miss while shaving your legs (mainly a girl problem). also known as a "knee beard."
Girl 1: I shaved my legs yesterday, but I know I forgot a spot.
Girl 2: Yeah, that's just like Janice. She always has knee whiskers!
Girl 2: Yeah, that's just like Janice. She always has knee whiskers!