dated A function corresponding to the rate of change of a variable quantity; a derivative.‘He integrated Leibniz's differential calculus and Newton's method of fluxions into mathematical analysis.’
- ‘For Newton integration consisted of finding fluents for a given fluxion so the fact that integration and differentiation were inverses was implied.’
- ‘I still must assert that this discovery appears to me to be as important for the middle of the nineteenth century as the discovery of fluxions [the calculus] was for the close of the seventeenth.’
- ‘Leibniz demanded a retraction saying that he had never heard of the calculus of fluxions until he had read the works of Wallis.’
- ‘He calls the quantity generated by a motion a fluent, and its rate of generation a fluxion.’
2 archaic mass noun The action or process of flowing or moving continuously; flux.
Mid 16th century from French, or from Latin flux- ‘flowed’, from the verb fluere.