The 80's term "Jellout' refers to someone who's brain has basically jelled. Or in other words, a brainless freak of sorts, similar to dweeb, idiot or fool.
"Oh man...Bob sure is being a 'Jellout' today. He is really getting on my nerves"...or "Did you see that guy walk out on the thin ice and jump up and down? What a 'Jellout'".
by SonoranSteve February 03, 2010