When one Sings and Humms at the same time! It is quite a pleasant sound a bit like a young walrus' mating call!
I was walking down the street Summing to myself
by Chemshotlord October 13, 2015

by EmptyPots March 28, 2015

Acronym for "Super Ultra Mega Slap"
Used when insulting or scolding someone for what one thinks is tasteless, immoral, or just fucking retarded.
May also be followed by an actual slap.
Coined in 2004, by a kid with an itchy fro and another kid who was just trying to fit in.
Used when insulting or scolding someone for what one thinks is tasteless, immoral, or just fucking retarded.
May also be followed by an actual slap.
Coined in 2004, by a kid with an itchy fro and another kid who was just trying to fit in.
by superskiier August 2, 2008

by averyone's mr tang April 12, 2021

by Sum's Lover November 12, 2003

A game where when someone says something stupid and you get to hit them on the head for it. After someone says the stupid statement, you immediately say "That's sum." while rubbing your fingers in the air like the sign for paying money.
Mick, "I drank 7 out of the last 5 days"
Al & Calvin, "That's sum, asshole (rubbing fingers in the air)."
then Al & Calvin each get to slap mick on the top of the head.
Al & Calvin, "That's sum, asshole (rubbing fingers in the air)."
then Al & Calvin each get to slap mick on the top of the head.
by a. ryan May 27, 2006
