VIPER

noun Etymology: Middle English ~e, from Latin ~a Date: 15th century 1. a common Eurasian venomous snake ( Vipera berus ) that attains a length of about two feet (0.6 meter), varies in color from red, brown, or gray with dark markings to black, and is usually not fatal to humans, a venomous or reputedly venomous snake, a vicious or treacherous person