Vipera berus

Adder Ad"der, n. [OE. addere, naddere, eddre, AS. n[ae]dre, adder, snake; akin to OS. nadra, OHG. natra, natara, Ger. natter, Goth. nadrs, Icel. na[eth]r, masc., na[eth]ra, fem.: cf. W. neidr, Gorn. naddyr, Ir. nathair, L. natrix, water snake. An adder is for a nadder.] 1. A serpent. [Obs.] ``The eddre seide to the woman.'' --Wyclif. Gen. iii. 4. ) [1913 Webster]

2. (Zo["o]l.) (a) A small venomous serpent of the genus {Vipera}. The common European adder is the {Vipera berus} or {Pelias berus}. The puff adders of Africa are species of {Clotho}. (b) In America, the term is commonly applied to several harmless snakes, as the {milk adder}, {puffing adder}, etc. (c) Same as {Sea Adder}. [1913 Webster]

Note: In the sculptures the appellation is given to several venomous serpents, -- sometimes to the horned viper ({Cerastles}). [1913 Webster]