This noun designates a poisonous snake, possibly derived from a root suggesting hissing. Isaiah 14:29 uses it in an oracle warning Philistia not to rejoice at the breaking of their oppressor's rod, for from the serpent's root will come forth something more deadly—a viper. The imagery builds from lesser to greater threat, using snake terminology to represent political dangers. The term emphasizes the venomous, deadly nature of the creature, not just any snake but specifically a dangerous one.