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

And for vipers, a 2013 study suggests the intense coloration can help the snakes regulate their temperature. —Eli Wizevich, Smithsonian Magazine, 19 Dec. 2024

At least one of the snakes that became loose was a small, highly venomous viper. —Charna Flam, People.com, 28 Nov. 2024

Julian’s quest for answers will only lure him deeper into this den of vipers, but teasing out Sofia’s intentions may be the steamiest — and deadliest — game of all. —Rosy Cordero, Deadline, 30 Oct. 2024

Snake Island, where the show staged challenges, was notorious for banded sea kraits and venomous vipers; the island was also a handoff point for pirates, which meant that it was patrolled by Australian special forces. —Emily Nussbaum, Vulture, 5 July 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