Fluxions

Part of speech: noun

Definitions

1. Rates at which quantities vary with time, as calculated in Newton's early form of calculus ; an archaic term for a steady flow or outpouring of something
2. The instantaneous rates of change of changing quantities, a concept from early calculus ; a old-fashioned word for a continuous stream or discharge of matter
3. Mathematical measures of how a varying quantity changes over time, developed in Newton's calculus ; a dated sense meaning a steady flow or emission

Etymology: "Fluxions" is the plural of "fluxion," a term that in its mathematical sense was coined by Isaac Newton for his method of calculus. Newton called the rate at which a continuously changing quantity grows its "fluxion," and the changing quantity itself a "fluent," so that a fluxion measured change in motion much as a speed measures the flow of a moving body. The word's deeper roots lie in the Latin "fluere," meaning "to flow." Its past participle "fluxus" gave Latin the noun "fluxio," meaning a flowing or flux, which passed through Late Latin into Middle French as "fluxion." English took it from there, so the modern sense of change over time is built directly into the word's ancestry: a fluxion is, quite literally, a flowing.

Synonyms: flux