from The American Heritage® Dictionary of the English Language, 5th Edition.

  • noun Any of various venomous snakes of the family Viperidae, having a thick heavy body and a single pair of long hollow fangs, especially the Eurasian and African species of the subfamily Viperinae, which lack the sensory pits of the pit vipers.
  • noun Any of several harmless snakes sometimes believed to be venomous.
  • noun A person regarded as malicious or treacherous.

from The Century Dictionary.

  • noun A venomous snake of the family Viperidæ: originally and especially applied to the only serpent of this kind occurring in the greater part of Europe, Vipera communis Or Pelias beruts.
  • noun Any venomous serpent except a rattlesnake; a viperine; a cobriform and not crotali form serpent, as a cobra, asp, or adder; also, loosely, any serpent that is venomous, or supposed to be so; a dangerous, repulsive, or ugly snake.
  • noun In heraldry, a serpent used as a bearing, some writers avoid the word serpent and use viper instead, there being no difference in the representations.
  • noun One who or that which is mischievous or malignant.

from the GNU version of the Collaborative International Dictionary of English.

  • noun (Zoöl.) Any one of numerous species of Old World venomous snakes belonging to Vipera, Clotho, Daboia, and other genera of the family Viperidæ.
  • noun A dangerous, treacherous, or malignant person.
  • noun Loosely, any venomous or presumed venomous snake.
  • noun (Zoöl.) See Cerastes.
  • noun (Zoöl.) the copperhead.
  • noun (Zoöl.) a small, slender, phosphorescent deep-sea fish (Chauliodus Sloanii). It has long ventral and dorsal fins, a large mouth, and very long, sharp teeth.
  • noun (Bot.) a rough-leaved biennial herb (Echium vulgare) having showy purplish blue flowers. It is sometimes cultivated, but has become a pestilent weed in fields from New York to Virginia. Also called blue weed.
  • noun (Bot.) a perennial composite herb (Scorzonera Hispanica) with narrow, entire leaves, and solitary heads of yellow flowers. The long, white, carrot-shaped roots are used for food in Spain and some other countries. Called also viper grass.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

  • noun A poisonous snake in the family Viperidae.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • noun venomous Old World snakes characterized by hollow venom-conducting fangs in the upper jaw


from The American Heritage® Dictionary of the English Language, 4th Edition

[Middle English vipere, from Old French, from Latin vīpera, snake, contraction of *vīvipera : vīvus, alive; see gwei- in Indo-European roots + parere, to give birth; see perə- in Indo-European roots.]

from Wiktionary, Creative Commons Attribution/Share-Alike License

From Latin vīpera.


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  • "One night last year in the king crab season, a 100-foot rogue wave with a 30-foot whitewater 'viper' slammed into Time Bandit. That frightened me beyond the measure of I-thought-we-were-done-for."

    —Johnathan and Andy Hillstrand with Malcolm MacPherson, Time Bandit: Two Brothers, the Bering Sea, and One of the World's Deadliest Jobs, 153

    see also growler.

    June 22, 2008

  • A prototype biplane fighter of the early 1920s. More on Wikipedia.

    December 30, 2008

  • The rare Iranian spider-tailed viper (Pseudocerastes urarachnoides) waggles a fake "spider"—actually a fleshy lure with leg-like scales at the tip of its tail—to tempt birds within striking distance.

    See video here:

    April 17, 2016

  • Why did the viper viper nose?

    April 17, 2016

  • Because the adder adder 'ankerchief.

    April 17, 2016

  • Why'd the angry viper viper nose?
    'Cause the adder adder 'ankerchief
    To 'elp 'er asp irate.

    April 18, 2016