adder

noun15

1. •
   A name loosely applied to various snakes more or less resembling a viper.
2. •
   (UK) A small venomous serpent of the genus Vipera

   • Entirely filled with the image of another, her heart, indeed, had the deaf ear of the adder, which heedeth not the voice of the charmer, charm he never so wisely. — 1834
3. •
   (UK) A common European adder (Vipera berus).
4. •
   A puff adder, of Africa (genus Bitis).
5. •
   (US, Canada) Any of several small nonvenomous snakes resembling adders
6. •
   (US, Canada) A milk snake (Lampropeltis triangulum).
7. •
   (US, Canada) A hog-nosed snake, of genus Heterodon of harmless colubrid snakes found in North America
8. •
   Certain venomous snakes resembling other adders
9. •
   Death adders (Acanthophis spp.), elapid snakes found in Southeast Asia and Australia
10. •
    A northern copperhead (Agkistrodon contortrix mokasen), a venomous viper found in the eastern United States
11. •
    Someone who or something which performs arithmetic addition; a machine for adding numbers.
12. •
    An electronic device that adds voltages, currents or frequencies.
13. •
    Something which adds or increases.

    • They sought out cost adders with an eye toward eliminating them.
14. •
    A sea stickleback or adder fish (Spinachia spinachia).
15. •
    (no longer used) Any snake.

noun1

1. •
   (informal) A person who has attention deficit disorder.

   • Many ADDers become targets for bullies and are routinely harassed at school. — 1996