any of various venomous or supposedly venomous snakes.
5.
a malignant or spiteful person.
6.
a false or treacherous person.
7.
(initial capital letter) Military. a 9-pound (4 kg), shoulder-launched, unguided U.S. Army antitank rocket with an effective range of 273 yds. (250 m).
—Idiom
8.
to nourish a viper in one's bosom, to befriend a person who proves to be treacherous.
[Origin: 1520–30; < L vīpera, haplological var. of *vīvipera, n. use of fem. of *vīviper, later (as re-formation) vīviparusviviparous]
Any of several venomous Old World snakes of the family Viperidae, having a single pair of long, hollow fangs and a thick, heavy body. Also called adder2.
A pit viper.
A venomous or supposedly venomous snake.
A person regarded as malicious or treacherous.
[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-1 in Indo-European roots.]
c.1520, from M.Fr. vipere, from L. vipera "viper, snake, serpent," from vivus "alive, living" (see vital) + parere "bring forth, bear" (see pare). It formerly was believed (mistakenly) that the viper does not lay eggs. Applied to persons of spiteful character since at least 1591. The only venomous snake found in Great Britain. Replaced native adder. "The flesh of the viper was formerly regarded as possessing great nutritive or restorative properties, and was frequently used medicinally" [OED]; hence viper wine, wine medicated with some kind of extract from vipers, used 17c. by "gray-bearded gallants" in a bid "to feele new lust, and youthfull flames agin."
Vi"per\, n. [F. vip[`e]re, L. vipera, probably contr. fr. vivipera; vivus alive + parere to bring forth, because it was believed to be the only serpent that brings forth living young. Cf. Quick, a., Parent, Viviparous, Wivern, Weever.]1. (Zo["o]l.) Any one of numerous species of Old World venomous makes belonging to Vipera, Clotho, Daboia, and other genera of the family Viperid[ae]. There came a viper out of the heat, and fastened on his hand. --Acts xxviii. 3. Note: Among the best-known species are the European adder (Pelias berus), the European asp (Vipera aspis), the African horned viper (V. cerastes), and the Indian viper (Daboia Russellii). 2. A dangerous, treacherous, or malignant person. Who committed To such a viper his most sacred trust Of secrecy. --Milton. Horned viper. (Zo["o]l.) See Cerastes. Red viper (Zo["o]l.), the copperhead. Viper fish (Zo["o]l.), a small, slender, phosphorescent deep-sea fish (Chauliodus Sloanii). It has long ventral and dorsal fins, a large mouth, and very long, sharp teeth. Viper's bugloss (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. Viper's grass (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.
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