Moon brain 

IQ above 5000 when you say or do something stupid

You're such a fucking Moon brain

Moon brain by (.Moth.) March 24, 2021

Bainbridge Moon landing 

The Bainbridge Moon Landing or "BML", is where a man or women accidentally touch arseholes. Similar to the standard "moon landing", where only baked bums need to touch, the BML however requires a singular accidental connection of the anus with another person's anus.

Becky and Jim we're trampolining naked, and fell on one another, accidentally connecting only their anuses, thus a Bainbridge Moon Landing or "BML"

Bainbridge Moon landing by Dobby1991 November 15, 2022

moonbrained 

A state of being unable to remember seemingly simple things such as keeping appointments and returning phone calls.

While occasionally a natural condition for some people, it is most often a temporary state triggered by excess stress and/or a lack of sleep. It should not be considered an accurate indicator of a person's intelligence.

I didn't mean to stand you up at the coffee shop last night. I got a bit moonbrained and completely forgot we had plans.

moonbrained by The Lord of Eltingville May 18, 2008

Monobrain 

Originally meant to be 'model brain', this got mis-heard as 'monobrain' and has been classic banter ever since.

Hey mate, can I have a look at your monobrain?

Monobrain by Barry June 4, 2004

Moonbrain 

The term used to describe what long term drug use effects the brain. Which is leaving small crater like surfaces in the surface of the brain.

"yoooo we did so much dope this weekend it was firrreee."

" You have a moonbrain bro."

Moonbrain by Sxpientia January 7, 2016