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

Amidst the many water monitors and garden lizards, guests might catch a glimpse of a snake lounging along the preserve, with resident species spanning from the Russell’s viper to the king cobra, a colossal creature that’s capable of measuring in at more than five meters in length. —Jared Ranahan, Forbes.com, 28 June 2025

This finding extends the geographic range of the Persian horned viper. —Real-Time News Team, Miami Herald, 20 June 2025

Snakes are all over the desert, hiding in plain sight, especially in Joshua Tree National Park, where people regularly hike and hang out without noticing any vipers. —Zoey Lyttle, People.com, 19 June 2025

The Nile vipers Crossword Clue Answer is... Answer: ASPS For more on USA TODAY's Crossword Puzzles Daily Crossword Analysis from Sally Hoelscher Sudoku & Crossword Puzzle Answers This crossword clue page was generated automatically using information from puzzles.usatoday.com. —Sally Hoelscher, USA Today, 18 June 2025

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

Rhymes for viper

• diaper
• hyper
• piper
• riper
• sniper
• wiper
• sandpiper

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