Broadly defined as anything that is very disgusting. Originally from the acronym "Mash Until No Good" from the practice of making many changes to a code until it is useless. Made popular from the Saturday Night Live sketch "Wayne's World", it was in the top 5 worst things to get in your halloween bag. It was mentioned again in South Park episode 317, this time more narrowly defined as a substance which comes out of a pregnant woman's vagina when pressure is applied to her stomach. And somehow an urban legend involving corpse fluids has sprung off the term mung, though there is no documentation supporting that this is anything other than a gross-out story.
The fraternity had a story about putting mung in the cookies they fed the freshmen. It was so gross!
by Monkeypirate December 10, 2005
Its the stuff that comes out when you push on a pregnant womans stomach
I gave that woman a hug and mung came out!
by Trisha F09630 November 14, 2008
In Australia, means to eat or devour something, usually quite enthusiastically.
I need to mung on something

I'm starving I wouldn't mind munging on a pie right now
by Antoi June 17, 2008
A type of Bean

The mung bean is the seed of Vigna radiata which is native to India. Mung beans are commonly used in Chinese cooking. Germinated mung bean sprouts (usually sold simply as 'bean sprouts') are stir fried (usually with ingredients such as garlic, ginger, spring onions or salted fish pieces to add taste) as a vegetable accompaniment to a meal. Uncooked bean sprouts are used in filling for Vietnamese spring rolls. Mung beans are also used to make a sweet soup, served either warm or chilled.
add three cups of mung beans for every 4 cups of water, bring to a boil
by Yonsen November 6, 2005
1. (verb) the act of digging up a recently deceased woman and putting your mouth up to her vaginal orfice while someone else stomps on her stomach forcing all of the fluids (from the vagina) into your mouth.

2. (noun) the literal vaginal secretions from the dead female once in your mouth
2. Josh's grandma died so Johnny and I munged her. The funeral was a munging good time.
by mr. mung March 6, 2005
Mung means some sort of idiotic person who sometimes could be smart

but sometimes can be dumb as shit.
{Naruto reference} Obito is a Mung so is Naruto
Being a mung is such a waste of personality
by Khups February 15, 2017
The accumulation of grease, hand lotion, dead skin, hair, Diet Coke, and food crumbs that accumulates on the rollers inside a computer mouse.
I had to go into Sherry's office about every four or five weeks and scrape the mung off the rollers in her mouse, when elsewhere in the department, this practice was necessary maybe once every eight or ten months (and most people were clever enough to figure out how to do it themselves).
by Spacklepants November 16, 2006