1 definition by rderickson9

To fuck off; It takes skill and dedication to say this to some one. You need to cough and say this at the same time, acting like you are coughing butyou are insulting the person at the same time; Not many people know of this technique so it is used well against teachers and also parents.
Mom- " Hey Jimmy, how was school today?"
Son- "Koff mom."
by rderickson9 August 26, 2010
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