water adder

• water-adder, wateradder

From Middle English water addre, watyradyr, watir edyr, alteration (see adder) of water neddyr, watyrnedyre, from Old English wæternædre, wæternǣdre, equivalent to water +‎ adder. Cognate with Dutch wateradder (“wateradder”), German Wassernatter (“watersnake”).

water adder (plural water adders)

1. Any of several aquatic snakes (none of which are true adders) including, among others:
   1. A non-venomous European ringed snake or water snake (Natrix natrix).
   2. A venomous American cottonmouth (Agkistrodon piscivorus).
   3. A non-venomous American northern water snake (Nerodia sipedon)
   4. A venomous South Asian crab-eating water snake (Fordonia leucobalia)

• watersnake