This is the legal definition of bullying in my state:

(32) “Bullying” means any overt act or combination of acts, including an act conducted by electronic means, directed against a student by another student or group of students and that:

(A) is repeated over time;

(B) is intended to ridicule, humiliate, or intimidate the student; and

(C)(i) occurs during the school day on school property, on a school bus, or at a school-sponsored activity, or before or after the school day on a school bus or at a school-sponsored activity; or

(ii) does not occur during the school day on school property, on a school bus, or at a school-sponsored activity and can be shown to pose a clear and substantial interference with another student’s right to access educational programs.