adder adder /ˈædər/

noun

1. Small terrestrial viper common in northern Eurasia  ( adder , common viper , Vipera berus )
   small terrestrial viper common in northern Eurasia
   
   
2. A machine that adds numbers  ( adder )
   a machine that adds numbers
    To speed up the calculation, he used an adder instead of doing it manually.
   To speed up the calculation, he used an adder instead of doing it manually.
   
   
3. A person who adds numbers  ( adder )
   a person who adds numbers