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A word commonly used in the place of Halloween by My Chemical Romance fans. It is stemmed from the birthday of rhythmic guitarist Frank Iero on the 31st of October.
Person: Happy Halloween!!
MCR fan: Suddafuckup, it's Ieroween!!

MCR fan: Happy Ieroween, Frankie!! How old are you today?
Frank Iero: Iero-what??
by iamamonster October 31, 2007
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