spontaneous weekend excursion 

The act of going somewhere without planning it.

Did you hear about John and Amanda? Their on there spontaneous weekend excursion! I think they went to California.

spontaneous weekend excursion by birse18 July 8, 2009

spontaneous gingerness 

when you wake up one day and suddenly, you're ginger!

*guy passes out from being drunk and wakes up the next morning*

Guy: Dude, i'm ginger now! Whats going on?

Girl: You've suffered a spot of spontaneous gingerness..

spontaneous gingerness by Leasperx March 10, 2010

Spontaneous Liquidation 

When a person, place or thing, unexpectedly dissolves into a puddle of liquid. Sometimes bursting like a water balloon or melting into a puddle, most likely killing them. Direct opposite of spontaneous combustion.

In the first X-men movie, the character Senator Kelly died by Spontaneous Liquidation.
Or
I was watching two men climb down a ladder when suddenly the first man ignited in spontaneous combustion, luckily at the same time the man man burst in spontaneous liquidation, putting the flames out.

Spontaneous Liquidation by BFew November 27, 2010

spontaneous carolling

The name for the common action of suddenly beginning to sing Christmas songs, no matter what season. Can include humming or whistling.

I'm known for my random outbursts of spontaneous carolling.

spontaneous carolling by helloitstess January 24, 2011

Spontaneous Moosination

The conglomeration of multiple lower level organisms to form a higher level organism. Most commonly used to describe the succession of mouse to moose.

"Spontaneous Moosination"

Several Mouse form a group of Mice.

Several Mice form a group of Meese

Several Meese form a Moose

Spontaneous Moosination by Physiology sucks November 29, 2011

Spontaneous pants off dance off 

When two or more parties spontaneously remove pants and challenge each other to a dance off, the winner of which may put pants back on and ridicule other(s) for being pantless.

Bro Emily totally dominated that spontaneous pants off dance off last night CJ was so ashamed she lost and had to remain pantless the rest of the night!

Spontaneous pants off dance off by emrahrah June 22, 2012

Spontaneous Tree Growth 

Similar to Morning Wood, spontaneous tree growth is a situation in which one gets a massive and long-lasting boner during daytime hours, usually at an inconvenient time such as during school or work.

David was totally about to get laid when he suddenly had a spontaneous tree growth, scaring off his prey.

Spontaneous Tree Growth by AwesomeScrewer August 23, 2014