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5.
A medical condition affecting the brain after listen to Fox News for three(3) consecutive hours.
He developed MUSH BRAIN after listening to Hannity, O'reilly and Great Van S in consecutive order.

He was fine doctor until he watched Fox for three hours when his brain turned to mush.
by PrinceofWheels July 25, 2009
 
1.
1.Old, burnt out,
2.What happens when you party and drink to much,
3.Used and abused also see maxhardcore,
4.Unaware of ones sorroundings,
5.One who cheats on tic-tac-toe,
6.Cracked out,
7.Why someone originated the qoute "theres a sucker born every minute",
8.Usually a girl that talks sh!t about something see has no idea about then you see her out and about and tries to say high, and her heels are ugly and has a flat butt. most often named nina.
red: do you want to chill with brad tonight
SEZk: naw mayn, your boy brad is such a mush brain.
red: hahahaha thats true. awsome dude

lucas: mayn that girl is on fire!
SEZK: get that! i got her on volume 2 and 3.
lucas: what ya talking bout sezk?
Sezk: ya didnt know? strait much brain. check phone photos.
Lucas: oh look!.. there she is.. with some lil boy shorts.
by SEZK GAMBINO June 01, 2007
 
2.
Decreased brain function, including (but not limited to) slower reflexes, confusion, and a lower IQ. This condition is observed:

1. In workers who spend greater than 8 hours a day and/or greater than 30 hours a week on excel

2. In North American citizens (particularly men) on the Monday after the Super Bowl

3. In athletes who have experienced many concussions
The professional hockey player was forced to end his career early due to mush brain after having numerous severe
by Mush Brain Patrol February 07, 2012
 
3.
The result occuring a day or so after smoking spice (such as K2) in which you experience slight memory loss and feel rather stupid for the whole day. Experts believe this is just a mental paranoia experience that can lead you to think you have something wrong with your brain.
Johnny- Fuck, I forgot about that homework, dude!
Tom- Probably cause of that K2 you smoked the other day.
Johnny- I think my brain is messed up dude!
Tom- You have massive Mush-Brain!
Johnny- Fuck Mush-Brain.
by UndercoverStoner February 01, 2011
 
4.
n. Any person who believes that feelings outweigh all other considerations, esp. in political speech. Often believes that any facts or evidence presented that may alter his/her feelings must be coming from someone who is one or all of: uneducated, hate filled, mean spirited, superstitious, racists. Uses the term "feels like" or "I feel" when asked for information or a fact.
Rochelle seemed like a classic mushbrain when told the policeman that she feels like the car was blue.

Jeff felt the teacher hated him when he got his grade in English. The teacher said he was a mushbrain, which made him feel better.

Trisha felt like Hilary should have won the primary.
by ilmotore October 22, 2008
 
6.
The effects the day after taking any form of the drug named MDMA. Usually involves laziness, slight depression, & slight memory loss.
Man: I don't feel like doing shit today. I have mush brain from partying last night.
by Dr. Seizure January 23, 2012