Basically an emphasis of for real. It comes from "fer serious" which is how people with bad grammar would say it. (Also "fo' cereal" or "fo' serious")
-Dude, I got free porn now.
-Fer cereal?! Awesome.
by Chris Leyva October 20, 2004
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Tiimmy: My mom got hit by a flying magic ice cream truck with 26 legs and a robo reptar cereal box arm!!

Jimbo: are you Fer-cereal?!?!?!?!!!?
by Rawrpeople April 25, 2010
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