To define something in its simplest terms after something is explained in a complex form, making the simple person look like a dumbass since everyone understood it the first time.

Origin - Gilligan from Gilligan's Island. He always did this when the Professor explained why something did or did not work
Classic Gilliganism:

Professor: "In order to make this new coconut-based radio function properly, we need an new receiving antenna installed on top of that coconut tree by the lagoon. In order to properly support it, someone will have to be ambidextrous."

Gilligan: "Yeah, and they have to use both hands,too."
by Dr. Freeze July 4, 2009
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A person or persons who have been marooned on a deserted island but find themselves in a pleasant situation.
Omg Did You Hear About Those People On The Island?

Yah I Heard They Were Gilliganed.
by klosekilla August 7, 2008
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A person of only some or no importance to a plot or situation, it's origins sprout from the Naruto Abridged Series, in which a little boy is referred to as Gilligan, and claims that is not his name and is ignored.
Person A: Come along Gilligan.
'Gilligan': That's not my name!
A: It is now.
'Gilligan': But I already have a name!
A: Come along Gilligan.
by A guy named Anonymous October 5, 2009
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A friendly and charismatic person. They enjoy going out and socialising with other people but are equally content staying indoors with a few close friends. Gilligans often struggle with self confidence issues deep down and often get addicted to a substance to help. This could be as little as a coffee addiction or as extreme as alcoholism or drug abuse. Gilligans are truely supportive friends and if you know a Gilligan in your life you sure are lucky! Just don’t forget to remind them that it’s okay to express how they feel.
“That’s my friend Gilligan over there”
“Wow he must be a lotta fun to be with
by Definition duderdude July 21, 2018
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“Yo I got hella gilly bro. Bro me to! how much cheese you got Himeenee? Yoooo I got hella cheese under my GILLIGAN!”
by Gilligan Island January 22, 2020
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Gi-li-gen Adjective
The type of woman you bang and then hope to god she gets shipwrecked on some uncharted desert isle so you and your friends never have to see her again.
"Awesome, Paul. She may be Gilligan, but at least you got your dick wet!"
by csalinas November 29, 2012
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Mr.howell hired Gilligan to make his life worth living so he got a bunch of intresting people and Gilligan kept Sabotageing there Escape and/or rescue to keep them all on Mr. Howell own little island for Mr.Howell own pathetic life
Mr.Howell was the millionare
he got a proffesor to keep them safe
then Maryanne for dinner
Ginger for eye candy
Skipper the true Dufus
His wife didn't have it in him to kill her
Gilligan the Orchestrator
by Hired Spy December 25, 2004
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