This word means "WRONG!" Utterly and completely wrong, at that.

Based on the loud, sudden, and decisively negative sound of a game-show buzzer.

Can also mean "No way!"
Ralph: "Joe, give me a bite of that sandwich."
Joe: "Mermp!"

or

Ralph: "Joe's mother wears army boots."
Joe: "Mermp!"

or

Ralph: "Joe, put your finger in these Vise Grips."
Joe: "Mermp!"
by The Nail Man September 3, 2009
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