A mental collection of visual images one stores in ones mind to remember later for purposes of 'self pleasure' see: masturbation. Entered into the spank bank are an array of images of people (usually ones you want to bone) in either suggestive or totally non-sexual situations generally seen in real life.
Ie; a girl in a mini skit, a low cut top and/or heels/A girl waiting at a traffic light eating a lollipop. A girl bending over to pick up a coin. A girl at a club making out with another chick.
A guy doing push-ups at the gym. Guys at the office etc...
Nate: Damn! did you see that bitch eat that banana?
Noun. A zoo of images one creates in his or her mind in order to be withdrawn at a later date to be used as assisistance while pounding one out. The bank is only temporary storage and is inferior in many ways to the cellular phone camera.
Noun: A folder on your computer dedicated for images taken from the internet and from social media websites like Facebook and Twitter of sexually attractive people for you to pleasure yourself to later.
A lazy, digital replacement for a regular spank bank that consists of images you remember in your head.
Person #1: "Hey dude, what's in that folder on your laptop called White Snake Lullabies?"
Person #2: "It's my spank bank folder man, it has nothing but naked porn stars and my hot Sorority friends in bikinis dude."
Person #1: "Why is it called White Snake Lullabies?"
Person #2: "It's an innuendo dude, I'm not stupid enough to call it Spank Bank."