vi·​per | \ˈvī-pər \

Definition of viper 

1a : 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

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Synonyms for viper


serpent, snake

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Examples of viper in a Sentence

a viper sliding silently through the field

Recent Examples on the Web

The viper is a blend between a linebacker and safety, and plays a role in seemingly every facet of the game. Orion Sang, Detroit Free Press, "Michigan football commitment Joey Velazquez a fit in defensive scheme," 23 June 2018 Still, genetic rescue has had successful outcomes too, for panthers in Florida, bighorn sheep in Montana, vipers in Sweden and others. Steph Yin, New York Times, "Arctic Foxes on a Swedish Mountain Turned ‘Blue.’ It Was a Good Thing.," 28 Mar. 2018 And yet scientists know surprisingly little about where all those geckos and vipers and iguanas and pythons came from. Sarah Kaplan,, "Meet the 240-million-year-old 'mother of all lizards'," 30 May 2018 The 6-foot-2, 180-pounder is a big hitter who flies to the ball and projects either as a rover (Michigan’s equivalent of a strong safety) or a viper. Orion Sang, Detroit Free Press, "Michigan football recruiting: Several top prospects still uncommitted," 2 July 2018 Michigan also has offered West Bloomfield 2019 4-star linebacker Lance Dixon, who projects as a viper in Brown's defense. Chris Nelsen, Detroit Free Press, "4-star prospect Marvin Grant Jr.: Recent contact with Michigan minimal," 10 Mar. 2018 The challenge for Succession is making viewers care about this nest of vipers, sniping and biting at each other for hours on end. Sophie Gilbert, The Atlantic, "Filthy Rich: The Power Plays of Succession," 2 June 2018 Some Folsom Lake boaters got a rude surprise last year when a viper crept onto their vessel. Benjy Egel, sacbee, "Young girl bitten by rattlesnake while playing on Effie Yeaw playground | The Sacramento Bee," 9 May 2018 Hudson spent last spring and offseason getting a crash course in how to play viper. Nick Baumgardner, Detroit Free Press, "What's next for Michigan's Khaleke Hudson? Anything he wants," 9 May 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'viper.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of viper

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

History and Etymology for viper

Middle English vipere, from Latin vipera

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Dictionary Entries near viper





viper's bugloss



Statistics for viper

Last Updated

10 Oct 2018

Look-up Popularity

Time Traveler for viper

The first known use of viper was in the 15th century

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More Definitions for viper



English Language Learners Definition of viper

: a type of poisonous snake


vi·​per | \ˈvī-pər \

Kids Definition of viper

: a poisonous heavy-bodied snake with long hollow fangs


vi·​per | \ˈvī-pər \

Medical Definition of viper 

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

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Comments on viper

What made you want to look up viper? Please tell us where you read or heard it (including the quote, if possible).


noxious or harmful

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