Flux

Etymology

From Latin fluxus, "a flowing," from fluere, "to flow" (also behind "fluid" and "influence"). It first named literal flows and discharges, then broadened to any state of continual change. The philosophical tag "everything is in flux," associated with Heraclitus, cemented its modern abstract use.

noun · /FLUKS/
Continuous change or unstable, ongoing movement.
What it names
The condition of something that will not hold still — constantly shifting, flowing, or being remade, so that no snapshot of it stays accurate for long.
Example
The department was in such flux that the org chart was out of date the day after it was printed.
Related idea
Stasis is its exact opposite — the standstill; flux is the restless motion that stasis lacks.
noun · /FLUKS/
A substance applied to metal before soldering or welding to clean the surfaces and help the joint fuse.
What it names
a metalworker’s aid — the paste or resin that lets molten solder flow and bond
Example
Brush a little flux on the copper pipe before you sweat the joint.
Related idea
The word’s root is flowing: here it makes solder flow, while in physics “flux” measures the rate something flows through a surface — magnetic flux, heat flux — both far from the everyday sense of ceaseless change.