noun
pronunciation- "Mist-er-ee Box"

A game usually played by, or in the company of males. A cooler filled with a random assortment of beers, including all varieties ranging from the shittiest of beers to the better tasting beers. When one has created this wonderful device, you are to stick your hand in the cooler and grab the first beer that luck grants you. After a beer is pulled from the cooler, it is dishonorable and highly frowned upon to replace said "shitty beer" with one that is more to your liking. It is absolutley prohibited to place your hand within the cooler without first finishing the open beer at hand. If a player is to do this, elimination from the game, castration, and execution are all possible forms of punishment.

Rules are open to interpretation. For example, if a less manly male has decided to place a beverage that is usually shunned from the male society into the mystery box(i.e. smirnoff ices or Mike's hard lemonade), there can be a democratic vote to create a rule in which one would have to chug every "less than manly beverage" upon removal from the cooler.

When you and your friends all cum inside of one girl and it’s a mystery of whose kid it is.

When a girl is such a slut it's a mystery which std's she gon give yo ass

This a motor vehicle used to take part in the Mystery box Rally.

The term arises from the fact that participants sign up to take part in the Mystery box rally without knowing what car they will be using or where they are going.
The cars are of unknown quality, and are usually secondhand cars that have been pulled out of the Manheim Auction System at random, and their value could be anywhere between $100 and $10,000.

The Mystery Box rally is a spin off of the Shitbox rally, and also raises money for the Cancer Council.

Someone, who when playing Zombies on COD, who will do anything including fuck up the whole game for a shot at the mystery box.

A man that is like a mystery box in that you wanna know about him until you find out about him and then say "why did i go with the mystery box?"

A collection of items, usually linked by brand or product type. They became popular since the 2010s.

Although they can be bought online, it is very easy to make a mystery box that contains items you have bought and sent it to someone.