\Flux"ion\, n. [Cf. F. fluxion.]
The act of flowing. --Cotgrave.

2. The matter that flows. --Wiseman.

3. Fusion; the running of metals into a fluid state.

4. (Med.) An unnatural or excessive flow of blood or fluid
   toward any organ; a determination.

5. A constantly varying indication.

         Less to be counted than the fluxions of sun dials.
                                               --De Quincey.

6. (Math.)
   (a) The infinitely small increase or decrease of a
       variable or flowing quantity in a certain infinitely
       small and constant period of time; the rate of
       variation of a fluent; an incerement; a differential.
   (b) pl. A method of analysis developed by Newton, and
       based on the conception of all magnitudes as generated
       by motion, and involving in their changes the notion
       of velocity or rate of change. Its results are the
       same as those of the differential and integral
       calculus, from which it differs little except in
       notation and logical method.