when a male masturbates harder than he normally does.

when you're hungover as shit after a spending a night drunk as a skunk

It is where you take the time to plan your masturbation session, meaning it involves thought from well before. It indicates the type of porn and porn stars etc are thought of in advance (YOU MUST BE EXCITED FOR THIS). You must be able to watch it with the sound at optimum level and have all videos (downloaded or streamed) ready to watch before you start. You should have the house to yourself so you can pleasure yourself however many times you feel necessary.

Smashturbate:
verb.
The action that takes place post partaking in a few rounds of the popular video game, Super Smash Brothers Ultimate, with a party of 2 or greater, where one is continuing, after all have ceased, lustfully towards gameplay, causing ya homie to play against the computer. and get fucked.

at a young age when a boy get his first boner and does not know what to do so he smashes it in between the fridge door

To smash out a quick furious wank ( Masturbate furiously)

to smash yourself