(n.) A swift coordinated move, in which the attacker approaches an unassuming victim who is standing up. The attacker kneels down and, with gusto and vim, sticks his/her arm between the victim's legs and reaches up to pinch the victim's belly. As this happens the attacker yells out, "Viper!!" Please note, the viper must be done with care, lest contact with other organs is accidentally made. (v. to viper) to give a person the viper
(n.) Oh my god, I can't believe that guy gave me the viper!
(v.) That's right, chump! You've just been vipered!