Someone who or something which performs arithmetic addition; a machine for adding numbers. / An electronic device that adds voltages, currents or frequencies. / Something which adds or increases.

(obsolete) Any snake. / (chiefly Britain) A small venomous serpent of the genus Vipera / The puff adders, of Africa (genus Bitis). / (US, Canada) Any of several small nonvenomous snakes resembling adders

plural of adder

(Oxford University slang, archaic) Addison's Walk, Magdalen College, Oxford.

A snake of the genus Acanthophis, a group of highly venomous elapids found in Australia and New Guinea. / The copperhead, a venomous pit viper species Agkistrodon contortrix, found in North America.

plural of adder's-tongue

Alternative form of puffadder

(electronics) A specific logical circuit that performs an addition operation on two bits.

(electronics) A specific logical circuit that performs an addition operation on three bits.

plural of adder fly