Invisible Pink Unicorn 

A supernatural creature whose existence can not be demonstrated, but for which certain facts are nevertheless asserted (if it's invisible, how do you know it's pink?).

Apparently orginating on the alt.athiest usenet group as a way to either argue the existence of God with non-athiests without getting personal, or mock them relentlessly. Sometimes shortened to IPU.

We know the Invisible Pink Unicorn exists, because no matter how hard hard we look we can't see her.

Invisible Pink Unicorn by irzebra March 19, 2004

invisible grapefruit clutch 

A heavy-metal hand gesture, in which the subject holds out their hand(s), palm up, fingers broadly curled inward, as if clutching an invisible grapefruit, or an orb of majestic evil power (still invisible).

When the throwing of horns got co-opted by the widespread public to the point where they were often seen from Jonas Brothers fans, Lord Blaspherion G. McSatan decided to adopt a more metal-centric hand gesture: the invisible grapefruit clutch.

invisible grapefruit clutch by Tyrannorabbit July 5, 2009

Invisible Children 

a shady, legitimate-looking scam that uses horrific events in africa to raise money for their own selfish interests. The fact that kony has been in hiding for 6 years, that the LRA currently numbers only a few hundred people, and the fact that only 32% of their funding actually goes to direct aid all points to some form of selfish use of the human emotions for personal gain. Even then, that direct aid involves funding rival militias and government armies all guilty of numerous human rights violations. There is already a manhunt for kony, your money is doing nothing to further that cause.

Teenager-omg kony 2012 i'm changing the world

wise one- bitch can it, Invisible children is just a scam designed to guilt-trip people out of their money using the plight of the victims of a now retired brutal warlord.

Invisible Children by anti-scampaigner June 20, 2012

Invisible Lat Syndrome 

The awkward stance that some males take in order to swell their chest in a ridiculous attempt at make non existing muscle seem present. Generally, the arms are lifted away from the body as if huge lat muscles were pushing them away. The author thinks that looking wide is the same as being wide and believes women will not see the difference.

Dave: Look at that skinny dude over there, he has no muscles but he is swelling himself up like a peacock!

Steve: Yeah he's got invisible lat syndrome, or ILS, common among douchbags who are too lazy to workout for their muscles!

Invisible Lat Syndrome by Lethal Interjection March 30, 2009

Invisible Rope 

When one person stands on each side of the street, and when a car comes by, they act as if playing tug of war across the street. I garuntee drivers will stop, thinking that something is there.

Fuck playing in traffic! Lets stop the cars by playin with our invisible rope.

Invisible Rope by Yo_Mommmmma January 6, 2009

invisible dog 

1.When a dog remains perfectly still while also averting his face to avoid attracting attention. Sometimes used in response to
the question "who ate my shoe?"
2.Can also be used by a person to the similar effect,see "invisible husband"

" Bart's effective use of invisible dog in the photo on petfinder.com got him a new home."

shy dog timid wasn't me silent invisible avoidance

invisible dog by Bart's Mom August 5, 2009

Invisible Laser Tag 

A game typically played by little kids and immature teenagers in which two players pretend to shoot each other with invisible laser guns while making shooting noises

A set of rules does not exist and both players can not die. Essentially the game goes on until either player is tired

Requires a very large imagination to play

That teenage girl must either have a really big imagination or just be really weird to play invisible laser tag

Invisible Laser Tag by Grade A Weirdo July 20, 2011