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1.
A gesture of anger or dislike toward a person or thing. Involves the clenching of all finger other than the middle finger, which should be in an erect position. For full effect, the surface of one's hand (not palm) should be directed toward the object or person of one's dislike.
I first heard it in South Africa, Kempton Park, where I grew up. Kids would call the middle finger the Zap Sign
synonyms: The middle finger; The Fuck-you-sign
When I cut the taxi driver off; He showed me a Zap-sign.
by wit of a twit October 28, 2004