marshmallowastic Posted in M Best definition marshmallowastic 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!!! How satisfied are you with the definition? Looking for marshmallowastic meaning? Delighted that you discovered the greatest determine on our web site! Recently this definition was actually observed 10 times.