1. Adjective: When a person or a group of people mess around and get absolutely nothing accomplished and just have fun. No sexual conduct of any kind is made.
2. Verb: When one decides to rub their genitals; See Masturbate, Masturbation. Sexual conduct can be made.
Guy 1: Hey man, you should join our Rugby Team, all we do is jack off during practice. It'll be fun
Guy 2: What kind of jacking off? Throw balls at each other? or just mess around and have fun?
Guy 1: Yeah, mess around man, not masturbate
Guy 1 sticks hand in pants and grabs genitals
Guy 2: EW MAN THATS GRODDY!