fluxion
The derivative of a function.
countable, obsolete, uncountable
The action of flowing.
archaic, countable, rare, uncountable
Perhaps he meant that towns are after all excrescences, grey fluxions, where men, hurrying to find one another, have lost themselves.
A difference or variation.
archaic, countable, rare, uncountable
Where it comes from
From Middle French fluxion, from Late Latin fluxiō, from Latin flūxus + -iō.
Adapted from the Wiktionary entry fluxion (CC BY-SA 4.0).