Methnesia 

loss of a large block of interrelated memories; complete or partial loss of memory caused by meth usage.

I'm Unable To Recall Where I Placed my car keys after we got home and I got totally spun out, but I I must have a bad case of METHNESIA.

Methnesia by Naughtyamazing22 December 29, 2017

Melanesia 

An island territory in the pacific that stretches from Fiji to West Papua.

Inhabited by warlike head hunting dark skin people who are considered superior then the soft gangsta wannabe polynesians.

European Explorer: oh my goodness, you chopped a jolly good fellows head off. Now i got blood all over me bloody english muffin and cup of tea.

Chief Kuloolai: Welcome to Melanesia motherfucker. What you thought this was?? Polynesia?? get the fuck outta here!

Melanesia by Alphonse Dau November 17, 2009

Mensnesia

The amnesia which women get while menstruating. The cycle causes forgetfulness and erratic behavior. Women can lose 25% of their IQ points during this time; making rational decision making an impossible task. Some have compared the experience to a mild form of Alzheimer’s. Don’t let this temporary slowness fool you, she will knock you out!

1. The woman couldn’t recall if she left her keys in the car or if the car was running, due to her mensnesia.

2. “Hey, I have mensenia, I can’t be expected to remember you have a food allergy!”

Mensnesia by TemptressTease December 11, 2021

Memenesia 

when a meme is no longer "cool" and you have to force yourself to never mention it ever again, so as to avoid being mistaken for a meme-layman. you repress its existance from your mind and live on in blissful ignorance, until another frog on a unicycle or some shit arrives and fills the deep void where your parents love should be.

low level meme folk: O SHIT WADDUP
triple lazer meme master: excuse me? im not sure exactly what you are referring to, its just a frog on a unicycle
-excerpt from "Memenesia and me, how i fought my forgetting"

Memenesia by TheMightySeanHub May 27, 2016

Mednesia 

The inability to recall if one has taken one's meds causing anxiety about either not taking them or double-dosing.

I really need to get one of those things daily pill holders because I constantly suffer from mednesia.

Mednesia by Hammer Bonespiel July 1, 2022

methesis 

A long rant on a social media site or forum, usually trying to convey the writer's point of view, relate a story, or explain their conspiracy theory. 'Methesis' is a portmanteau of 'meth'(amphetamine) and 'thesis', which is often a long written document, often hundreds of pages in length, written as the culmination of a research project or term of study.

Damn, that tweaker left us a methesis paper on why he shouldn't be banned because the CIA is spying on his computer.

I got a methesis from my employee today about why he was too sick to work. If he kept it short, I might have believed him.

methesis by TK421isAFK July 9, 2023

melanesia 

An island territory in the south pacific.

Melanesia is by Malaysia.

melanesia by JOHNSON October 18, 2003