معنی کلمه :‌ adder

A serpent.

Same as Sea Adder.

One who, or that which, adds; esp., a machine for adding numbers.

Sister. [Obs.] Chaucer. There are seven sustren, that serve truth ever. Piers Plowman.

In America, the term is commonly applied to several harmless snakes, as the milk adder, puffing adder, etc.