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the pronouciation of the acronym STFU which means shut the fuck up. Stiffoo is just a better way of trying to say the letters, or more pg way of saying the full meaning. It also seems to lose some of its aggresion with the abbrivation.
person 1: so i was like 'blah blah blah' after she was all 'yadda yadda yadda'
person 2: god, stiffoo!

person A: stiffoo noob!
person B: why dont you just swear like a normal person?
by anevilscientist September 10, 2007
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