adder
n. countablen. a type of snake that is common in Europe and parts of Asia. It is usually brown or grey and has a distinctive V-shaped mark on its head.
n. a venomous snake of the genus Vipera, native to Europe and parts of Asia. Characterised by a triangular head and a zigzag pattern along the back.
The hiker saw an adder resting in the grass.
While walking through the meadow, we were warned to watch for the local adder population.
The European adder is one of the few venomous snakes found in the British Isles, though its bite is rarely fatal to healthy adults despite the potent neurotoxins it produces.
From Middle English nadder, addere, rebracketing of “a naddere” as “an addere”, from Old English nǣdre (“snake”), from Proto-West Germanic nadrā, from Proto-Germanic nadrǭ, from pre-Germanic néh₁treh₂, variant of Proto-Indo-European n̥h₁trih₂, from *(s)neh₁- (“to spin, twist”). See also West Frisian njirre, Dutch adder, German Natter, Otter; also Welsh neidr, Latin natrīx (“watersnake”), Dutch naaien.
From add + -er.