A female, usually older, who possesses a large crusty cavity and uses it to entrap young teenage schoolboys. (verb: Kavvied)
Student 1: Woah did you see that new English Teacher?
Student 2: Yeah I bet she's a real Kavvy.
Student 1: Man I am so tired today..
Student 2: Why is that dood?
Student 1: Got Kavvied last night..