fluxion

flux +‎ -ion

fluxion (countable and uncountable, plural fluxions)

1. (obsolete, mathematics) The derivative of a function.
2. (rare or archaic) The action of flowing.
3. (rare or archaic) A difference or variation.

fluxion (third-person singular simple present fluxions, present participle fluxioning, simple past and past participle fluxioned)

1. (geology) To be distributed in a flowing pattern.
   • 1982, Charles James Hughes, Igneous petrology, →ISBN, page 142:

     ...pilotaxitic texture connotes abundant plagioclase microlites prominently fluxioned in an overall sub-parallel manner and locally around phenocrysts (but strictly in a holocrystalline non-glassy matrix).

• fluxional