When a person at a concert is trying to dance and sing along but is incredibly off beat and usually mouthing the wrong words. The opposite of jamming.
"I'm never taking Derek to a concert again. He was jellying all over the place with no sense of direction or rhythm."
"Do you see the guy with his hippiegirlfriend in front of us?"
"Yeah, he's really spreading out his jelly!"
"Couldn't agree more, man Phish is awesome!"
(v.) To force jello through your teeth onto your chin. Most commonly used as an expression of sexual attraction and as a form of foreplay.
Comes from the fact that jello is simply a sexy food. Also reminiscent of bodily fluids exchanged during sexual intercourse.
"Mary, I find you irresistible! Let's jello!"
"Man, those two are all over each other! They were even jelloing in Starbucks the other day!"
"Yeah, and then we jelloed! You can bet it was the best sex we ever had!"