look up any word, like swag:
 
1.
Instead of staying after school for extra-curricular activities you stay for sextra-curricular ones. Which usually involve a teacher, a student and a desk. Often related to trying to get sextra credit, but it can just be for the heck of it.
Student 1: Are you catching the bus tonight?
Student 2: Nah, I've got to stay behind for some sextra-curricular activities or else I'm going to fail geography.
by Rotutsu April 30, 2011
4 2
 
2.
Having an affair, specifically one that exists almost solely for sex.
His girlfriend thinks they're in a monogamous relationship but she is completely unaware of his sextracurricular activities.
by iowabuckeyes January 11, 2010
2 2