A person who is "jelly" or jealous. They are often found ridiculing other's acheivments.
Guy 1: Hey bro, check out my new rims.
Guy 2: They suck, man.
Guy 1: Wow, you really are a jellyfish.
Guy 2: I'm not a jellyfish!
Guy 1: Yes you are.
Guy 2: Am not.
Guy 1: Are to.
Guy 2: Am not.
Guy 1: Are to.
Guy 2: Okay.
by HushPuppy June 29, 2012
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The ability to ejaculate with a half-erect penis, usually caused by narcotics or alcohol
Whoa I was rockstar drunk last night, I totally jellyfishes whats-her-pickle and got outta there fast
by Burnaby_Bo July 11, 2011
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A woman who is great to look at, but dangerous to get close too.
"She's hot! Too bad she's a jellyfish... That girl is crazy as hell, she'll stab you during foreplay..."
by DaRealMan March 13, 2013
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A Jellyfish is what you make when you wack off into a glass of water. The result is a partially floating, dangling, jizz strand that looks like a jellyfish.
"So did you hook up with whats-her-name last night?"

"No dude, I just went home and made a jellyfish."
by El Spicy Taco August 21, 2008
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Awesome. Really cool. A common synonym is: bomb, but cannot be used with 'the' preceding the word.

'The Jellyfish' is incorrect.

'Jellyfish' is correct.
Person A "Dude, why are you allowed to do that...?"
Person B "Cos I'm Jellyfish..."

Person A "DUDE LOOK AT THAT THING OVER THERE. it's jellyfish!"
by chiangchiangchiangchiangchiang December 6, 2010
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A game not commonly played. The object is to not be the last person to say Jellyfish.
Someone shouts out 'jellyfish' and everyone has to say, 'jellyfish'. The last person to say this says 'I am not a jellyfish'.

Then everyone laughs at them.
David: "Jellyfish!"
Jake: "Jellyfish-"
Becki: "-jellyfish-"
Simon: "I am NOT, a jellyfish."
by Pseudonymrawr June 13, 2010
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