adder

1. N-COUNT In North America, a number of different poisonous and non-poisonous snakes are called adders. In Europe and Asia, an adder is a small poisonous snake that has a black pattern on its back. (北美产的)多种蛇的通称; (欧亚产的)蝰蛇

2. N-COUNT a person or thing that adds, esp a single element of an electronic computer, the function of which is to add a single digit of each of two inputs 加法器