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A person who REALLY knows when people lie and tells them to their face.
man 1: I'm not gonna be here on saturday *giggles while looking at man 3 play DooM instead of making eye contact and being honest*

Man 2: (I know he's lying.) YOU LIE!

Man 3: OOH! The Liar Alarm is going off! *punches man 1 for lying*
by Buzzed Lightbeer January 30, 2006
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