A mushroom cloud is a distinctive fiery mushroom-shaped cloud of condensed water vapor or debris resulting from a very large explosion. They are most commonly associated with nuclear explosions, but any sufficiently large blast will produce the same sort of effect. They can be caused by powerful non-nuclear weapons like the GBU-43/B Massive Ordnance Air Blast bomb. Volcano eruptions and impact events can produce natural mushroom clouds.

Mushroom clouds are formed by many sorts of large explosions under earth gravity, near the ground. Mushroom clouds form as a result of the sudden formation of a large mass of hot, low-density gases near the ground creating a Rayleigh-Taylor instability. The mass of gas rises rapidly, drawing up a column of additional smoke and debris in the center to form its "stem". The mass of gas eventually reaches an altitude where it is no longer of lower density than the surrounding air and disperses, forming the "head".

Nuclear mushroom clouds are often also accompanied by short-lived vapor rings around the stem, called "Wilson clouds". These are created by the blast wave causing a sudden drop in the surrounding air temperatures, causing water vapor in the air to condense around the explosion cloud's "stem".

Mushroom clouds cannot form after an explosion high in the air, under water, or in space. In space the explosion would be somewhat spherical.
goddammit people a mushroom cloud is a physical phenomenon not a sexual move
by Young Reezie December 14, 2009
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NOUN: the spare-tire/belly fat that is forced over an overweight person's too-tight jeans. (resembles a mushroom cap)
When Rosie O'Donnell puts on a pair of size 20 jeans, her mushroom cloud is considered a weapon of mass destruction.

or "Sure, i can fit into size 6, but it gives me a mushroom cloud"
by slothymcgee February 12, 2008
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muffin top + camel toe = mushroom cloud.
Rosie O'Donnell in a half shirt and skinny jeans?! Her mushroom cloud must be deadly.
by ducttapedoc October 14, 2010
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When you slap another person on their forehead with your dick.
this chick was passed out at a party do I gave her a mushroom cloud.
by 4Q2pal October 25, 2007
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1.the end result of a nuclear explosion
2.the solution to all of the world's problems
by D3zNu7$ February 18, 2008
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Powerful Voluminous Ejaculation.

Named as such because it shoots from the mushroom shaped penis head and often forms random shapes where it lands much like clouds do.
I hammered my girlfriends "Cockgarage" so hard that I shot my "Mushroom Cloud" all over her "Double Stuffed Oreo's"
by Jeff D April 21, 2003
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1. The resulting cloud after a nuclear detonation.

2. To describe a person a person who is really, really mad.
Jeff's gonna lay a mushroom cloud when he finds out your bangin' his mom.
by Blowfish July 24, 2005
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