Learn how to say Adders correctly in English with this tutorial pronunciation video.
Oxford dictionary definition of the word adder:
a small venomous Eurasian snake which has a dark zigzag pattern on its back and bears live young. It is the only poisonous snake in Britain. Also called viper.
Vipera berus, family Viperidae
used in names of snakes that are similar or related to the adder, e.g. death adder, puff adder.
Old English nædre ‘serpent, adder’, of Germanic origin; related to Dutch adder and German Natter. The initial n was lost in Middle English by wrong division of a naddre; compare with apron, auger, and umpire