marshmallowastic Share definition Flag a term for when someone has an orgasmic reaction to a marshmallow. Person 1: hey how were those marshmallows? Person 2: OH MY GOD THEY WERE MARSHMALLOWASTIC!!! marshmallowastic by widevirus February 24, 2010 0 0 Get merch Get the marshmallowastic mug. Buy Now — $32.95 See more merch