A natural disaster caused by an extreme excess of smegma concealed in one's own foreskin. Usually caused by not cleaning your foreskin on the regular or from dietary problems resulting in a sudden growth of smegma.
Bill: Hey man are you going to the game tomorrow?
Fred: Nah man my family and I are getting out of town before the Smegmageddon gets here.
Bill: OH SH*T I GOTTA GET OUTTA HERE!
Fred: Yeah dude, it's pretty tragic.
by Grandpa Bob June 28, 2016
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