Main Entry: ¹ad·der

Pronunciation: \ˈa-dər\

Function: noun

Etymology: Middle English, alteration (by false division of a naddre) of naddre, from Old English nǣdre; akin to Old High German nātara adder, Latin natrix water snake

Date: 14th century

1 : the common venomous viper (Vipera berus) of Europe; broadly : any of various snakes of the viper family — compare puff adder
2 : any of several North American snakes (as the hognose snakes) that are harmless but are popularly believed to be venomous

[adder illustration]