1.The act of flowing; a continuous moving on or passing by, as of a flowing stream; constant succession; change. " By the perpetual flux of the liquids, a great part of them is thrown out of the body." "Her image has escaped the flux of things, And that same infant beauty that she wore Is fixed upon her now forevermore." " Languages, like our bodies, are in a continual flux."
2.The setting in of the tide toward the shore, the ebb being called the reflux.
3.The state of being liquid through heat; fusion.
4.(Chem. & Metal.) Any substance or mixture used to promote the fusion of metals or minerals, as alkalies, borax, lime, fluorite. Note: White flux is the residuum of the combustion of a mixture of equal parts of niter and tartar. It consists chiefly of the carbonate of potassium, and is white. Black flux is the ressiduum of the combustion of one part of niter and two of tartar, and consists essentially of a mixture of potassium carbonate and charcoal.
6.(Physics) The quantity of a fluid that crosses a unit area of a given surface in a unit of time.