Idempotence

Part of speech: noun

Pronunciation: /ˌɪdɛmˈpəʊtəns/

Definitions

1. A concept in mathematics where an operation produces the same outcome regardless of how many times it is applied
2. A characteristic describing functions or operations that yield identical results upon repeated executions without alteration
3. The property of a process or function that gives the same output no matter how many times it is executed in succession

Etymology: Benjamin Peirce, the nineteenth-century American mathematician, coined this term in the context of algebra. He needed a name for a property some operations have: applying them to a value once or many times makes no difference. Peirce built it from the Latin "idem," meaning "same," and "potence," the quality of having power. Put together, the word literally describes the quality of having the same power each time. The "potence" element comes from the Latin "potentia," which gives English words such as potency and potent. Peirce's coinage keeps that sense of force or capacity, so an idempotent operation has the same effect however many times it is repeated. Because the word was made deliberately from classical parts rather than inherited from older English, its meaning was fixed from the start, with no drift from its original sense.