A bored wank (masturbating). Usually done when you have nothing else to do or don't want to do anything. Can also happen in the middle of porn when it starts getting shit.
I tried to think of what to do today, then I have up and just had a bank.
I saw this pornstar sucking off some dude but it got boring, so I just banked through it.
-to bank somebody
Willingness for future sexual encounter with a person. Means that one would willingly share her/his gene bank (pool) with the significant other.