viper

noun

vi·​per ˈvī-pər 

1

a

: 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

broadly : any of a family (Viperidae) of venomous snakes that includes Old World snakes (subfamily Viperinae) and the pit vipers

b

: a venomous or reputedly venomous snake

2

: a vicious or treacherous person

Synonyms

• serpent
• snake

Examples of viper in a Sentence

a viper sliding silently through the field

Recent Examples on the Web

This viper hunts by hiding in rocky crevices, revealing only its tail above the surface. —Scott Travers, Forbes, 21 Sep. 2024

For centuries, myths and fairytales from European folklore have warned of the danger of the common adder (Vipera berus), a venomous viper known for its painful—although not particularly dangerous—bite. —Byphie Jacobs, science.org, 20 Sep. 2024

However, the Gaboon viper outdoes them both by delivering a staggering 200-1000 mg per bite. —Scott Travers, Forbes, 7 Sep. 2024

The rabbits’ range has shrunk over the years, and the rabbits have also been preyed upon by invasive mongooses that had been introduced to curb viper populations in the area. —Kate Golembiewski, Discover Magazine, 1 Aug. 2024

Word History

Etymology

Middle English vipere, from Latin vipera

First Known Use

15th century, in the meaning defined at sense 1a

Phrases Containing viper

• horned viper
• pit viper
• viper's bugloss

Kids Definition

viper

noun

vi·​per ˈvī-pər 

1

: any of a family of poisonous snakes having heavy bodies, broad heads, and hollow tube-shaped fangs and including Old World snakes and the pit vipers

2

: any snake that is poisonous or that is believed to be poisonous

Medical Definition

viper

noun

vi·​per ˈvī-pər 

1

: a common Eurasian venomous snake of the genus Vipera (V. 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 whose bite is usually not fatal to humans

broadly : any snake of an Old World subfamily (Viperinae) of the family Viperidae

2

: pit viper

3

: a venomous or reputedly venomous snake