1) verb; to destroy objects in your surrounding area while making an over-the-top attempt to kill an insect.
2) verb; to destroy ANYTHING in your surrounding area due to unnecessary exuberance and really putting a damper on the evening.
3) noun; to be the person who ruined the evening due to over-exuberant gestures causing unneeded cleanup and the loss of personal possessions.
"You completely rumstummed my entire collection of hummel figurines over an insignificant mosquito!"
"Chill out Gregory, thats the third glass you've broken today, its only a WNBA game, who's the Rumstum now?"
"Katie is a fucking rumstum. and i hate her ugly face and guts."