A 1-10 also read 110, one-ten, is the numerical discreption for something that is 110% sketch. It is often used to decribe females that are not up to your friends standerds but are willing and able. A 110 often falls on your lap after a night of inebriation. Sometimes also reffered to as tenners.
Friend 1: Yoo, whats good?
Friend 2: Not to much chillin...
Friend 1: Heard you hooked up with a chick last night?
Friend 2: Yeah it was straight
Friend 1: Did you kiss her?
Friend 2: Hell nah she was a 1-10.