When you agree with something just that much. Said at top volume, in a resinous Patrick Stweart-esque voice, head tilted to side, with emphatic thumbs up motion.
"Ahh man, it's well raining."

"MEGAGREE!"

or

"Did you want sauce with that?"

MEGAGREEE!!!!!

(Shouted into the poor subway guys face.)

*see youtube video, MEGAGREE
by molokovesper - megagreeman January 10, 2012
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A word that means you really agree, roots from mega and agree (meg-uh-gree)
person one- Dude the chick on that movie last night was fucking hot

person two- I know right? I totally megagree
by ghet0asassin January 1, 2010
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