[ fluhk-shuh n ]
/ ˈflʌk ʃən /


an act of flowing; a flow or flux.
Mathematics. the derivative relative to the time.

Origin of fluxion

1535–45; < Middle French < Late Latin fluxiōn- (stem of fluxiō) a flowing. See flux, -ion

Related forms

flux·ion·al, flux·ion·ar·y, adjectiveflux·ion·al·ly, adverb
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for fluxional

British Dictionary definitions for fluxional


/ (ˈflʌkʃən) /


maths obsolete the rate of change of a function, especially the instantaneous velocity of a moving body; derivative
a less common word for flux (def. 1), flux (def. 2)

Derived Forms

fluxional or fluxionary, adjectivefluxionally, adverb

Word Origin for fluxion

C16: from Late Latin fluxiō a flowing
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012