Ăd'der, n.
n. [A-S. ætter, ættor, atter, attor, serpent, poison, O. H. Ger. eitar, L. Ger. etter, N. H. Ger. eiter, poison, matter, D. adder, Ger. otter, serpent, A-S. nædre, næddre, serpent, Goth. nadrs, O. Sax. nadra, Icel. nadr, m., nadra, f., O. H. Ger. natra, natara, N. H. Ger. natter, W. neidr, Corn. naddyr, Ir. nathair, Lat. natrix, from nare, to swim.]
Sense 1. (Zoöl.) A venomous serpent of the genus Vipera. The common adder is the Vipera berus. Baird.
Sense 2. A serpent in general. Milton.
Sense 3. (Ichth.) The same as SEA-ADDER.