n. A euphemism for masturbation in reference to the song "All By Myself." Used mostly by ugly-ass high school girls passing notes at the Twins game next to the left field pole.
Ugly Girl 1: I've been Greendaying every once in a while, but i really don't think about Jesse all that often. I swear.
Ugly Girl 2: Eeeeeww!!!
1. adj. describes an object, person, or situation which is gay, but not in that cool man-love sorta way.
Steve got cuffed and thrown in the back of a cop car for throwing a f**king snowball? That's gaytron.