adder

plural adders · alternative dialectal edder

1. obsoleteAny snake.

   1 more example

   CALIBAN: His spirits hear me, / And yet I needs must curse. But they'll nor pinch / Fright me with urchin-shows, pitch me i'th' mire, / Nor lead me like a firebrand in the dark / Out of my way, unless he bid 'em; but / For every trifle are they set upon me, / Sometimes like apes that mow and chatter at me, / And after bite me; then like hedgehogs, which / Lie tumbling in my barefoot way, and mount / Their pricks at my footfall; sometimes am I / All wound with adders, who with their cloven tongues / Do hiss me into madness—

   1610–1611 (date written), William Shakespeare, “The Tempest”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, →OCLC, [Act II, scene ii]

2. A name loosely applied to various snakes more or less resembling a viper.
   1. UKA small venomous serpent of the genus Vipera

      These include the county's [Cumbria's] only venomous snake - the adder - which relies on exposed elements to successfully breed its young.

      2021 August 25, Nick Brodrick, “Flourishing Flora and Fauna”, in RAIL, number 938, page 51

      1 more example

      Entirely filled with the image of another, her heart, indeed, had the deaf ear of the adder, which heedeth not the voice of the charmer, charm he never so wisely.

      1834, L[etitia] E[lizabeth] L[andon], chapter XXX, in Francesca Carrara. […], volume III, London: Richard Bentley, […], (successor to Henry Colburn), →OCLC, page 245

   2. UKA common European adder (Vipera berus).
   3. A puff adder, of Africa (genus Bitis).
   4. CanadaUSA milk snake (Lampropeltis triangulum).
   5. CanadaUSA hog-nosed snake, of genus Heterodon of harmless colubrid snakes found in North America
   6. Death adders (Acanthophis spp.), elapid snakes found in Southeast Asia and Australia
   7. A northern copperhead (Agkistrodon contortrix mokasen), a venomous viper found in the eastern United States
3. A sea stickleback or adder fish (Spinachia spinachia).

plural adders

1. Someone who or something which performs arithmetic addition; a machine for adding numbers.
2. An electronic device that adds voltages, currents or frequencies.
3. Something which adds or increases.

   They sought out cost adders with an eye toward eliminating them.

plural ADDers

1. informalA person who has attention deficit disorder.

   Many ADDers become targets for bullies and are routinely harassed at school.

   1996, David Sosin, Attention Deficit Disorder, page 54