The act of playing Minecraft. Usually refers to someone that is hopelessly addicted to Minecraft. Generally is used when someone plays Minecraft for hours on end.
Loren: "Hey man, what are you doing today?"
Tyler: "I'll probably just Minecrafterbate all day."
"Hey bro, you and Ryan should come over and we can start a circle jerk of Minecrafterbation."
Loren: "Have you seen Tyler lately?"
Ryan: "No, I think he's been Minecrafterbating for the last few days."
Tyler: "Dude, my arm is so sore, I was minecrafterbating for like 10 hours straight today!"
Contrary to popular belief, a Minecrafter is not a lazy bum, rather a person who prefers to use their imagination compared to people who sit around and shoot virtual guns at other players.
Also, someone known as a nerd, geek, etc.
That Minecrafter guy...he sure seems to play it a lot.