An insane dude. Someone who is out of his god damn mind. A guy that did something that nobody would have ever even dared to think of doing.

The safeguarding of Earth and other worlds from biological cross-contamination (i.e. billionaires with too much time on their hands).

Also known as “planetary protection.” Planetary protection / quarantine “reflects both the unknown nature of the space environment and the desire of the scientific community to preserve the pristine nature of celestial bodies until they can be studied in detail.”

There are two types of interplanetary contamination. Forward contamination is the transfer of viable organisms from Earth to another celestial body. Back contamination is the transfer of extraterrestrial organisms, if such exist, back to the Earth's biosphere.

An absolute unit or uncontainable beast of destruction that will never stop pushing down walls of pure power and death to make the world a better place.

Someone who actually does it

A person who is a complete savage and/or a crazy risk taker, often used sarcastically.

A madlad is a dude that did something so incredibly extreme, so fundamentally unbelievable, that everyone just wonders in awe after him. Someone out of their god damned mind who did something that no sane person would have thought possible. It is often preceded by the word “absolute”.

A Mad lad is somebody who does something extreme, like trying to get inside jokes into the urban dictionary.