• synonyms


See more synonyms on Thesaurus.com
  1. the common European viper, Vipera berus.
  2. any of various other venomous or harmless snakes resembling the viper.

Origin of adder1

before 950; late Middle English; replacing Middle English nadder (a nadder becoming an adder by misdivision; cf. apron), Old English næddre; cognate with Old Saxon nādra, Old High German nātara (German Natter), Old Norse nathra snake, Gothic nadrs adder, Old Irish nathir snake, Latin natrix water snake


  1. a person or thing that adds.

Origin of adder2

First recorded in 1570–80; add + -er1
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for adder

Historical Examples

  • It is more venemous than the adder, it is more destructive than hebenon or madragora.


    William Godwin

  • Afterwards he seized hold of an adder, and was not bitten by it.


    James Anthony Froude

  • Monsey jumped, with a scream, out of his seat as though stung by an adder.

  • Burke started, as if the tones of his companion's voice had stung him like an adder.

    Jack Hinton

    Charles James Lever

  • The good Book says, 'it biteth like a serpent and stingeth like an adder!'

    Uncle Tom's Cabin

    Harriet Beecher Stowe

British Dictionary definitions for adder


  1. Also called: viper a common viper, Vipera berus, that is widely distributed in Europe, including Britain, and Asia and is typically dark greyish in colour with a black zigzag pattern along the back
  2. any of various similar venomous or nonvenomous snakes

Word Origin

Old English nǣdre snake; in Middle English a naddre was mistaken for an addre; related to Old Norse nathr, Gothic nadrs


  1. a person or thing that adds, esp a single element of an electronic computer, the function of which is to add a single digit of each of two inputs
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for adder


Old English næddre "a snake, serpent, viper," from West Germanic *nædro "a snake" (cf. Old Norse naðra, Middle Dutch nadre, Old High German natra, German Natter, Gothic nadrs), from PIE root *netr- (cf. Latin natrix "water snake," probably by folk-association with nare "to swim;" Old Irish nathir, Welsh neidr "adder").

The modern form represents a faulty separation 14c.-16c. into an adder, for which see also apron, auger, nickname, humble pie, umpire. Nedder is still a northern English dialect form. Folklore connection with deafness is via Psalm lviii:1-5. The adder is said to stop up its ears to avoid hearing the snake charmer called in to drive it away. Adderbolt (late 15c.) was a former name for "dragonfly."

Online Etymology Dictionary, © 2010 Douglas Harper