ENGLISH
REFERENCE

flux

n. · v.
US //ˈfɫəks// UK //flˈʌks// flux
  1. 1 constant change (n.)
    B2 Upper Intermediate

    a state of continuous change or movement where nothing stays the same for long.

    a state of continuous change, instability, or fluctuation.

    Example

    The company's leadership has been in a state of flux for several months.

    Example

    The political landscape remained in constant flux as shifting alliances made it impossible to predict the outcome of the upcoming vote.
  2. 2 energy transfer (n.)
    C1 Advanced Technical Science

    the rate at which energy or a liquid flows through a specific area.

    the rate of flow of a physical property, such as energy or particles, through a given surface.

    Example

    The scientist measured the magnetic flux passing through the copper coil.

    Example

    Calculating the radiant flux is essential for determining how much solar energy actually reaches the surface of the planet.
  3. 3 metal cleaning agent (n.)
    C1 Advanced Technical Technical

    a substance used to clean metal surfaces so they can be joined together easily by soldering.

    a chemical agent used in soldering, brazing, or welding to clean the metal surface and prevent oxidation.

    Example

    You need to apply flux to the wires before you try to solder them together.

    Example

    Without the application of a high-quality flux, the solder will fail to adhere to the oxidized copper pipes.
  4. 4 bodily discharge (n.)
    C2 Proficiency Archaic Medicine

    an old word for a disease that causes a lot of liquid to leave the body, like diarrhea.

    an excessive discharge of blood or fluid from the body, historically associated with dysentery.

    Example

    The old journals described a bloody flux that affected many soldiers in the camp.

    Example

    Historical accounts of the siege mention that more men succumbed to the flux than to actual combat injuries.
  5. 5 to melt (v.)
    C2 Proficiency Technical Science

    to make something become liquid using heat.

    to cause to become fluid; to fuse or melt through the application of heat.

    Example

    The intense heat of the furnace began to flux the raw ore.

    Example

    The minerals were fluxed at extremely high temperatures to separate the precious metals from the surrounding rock.
Origin

From Old French flux, from Latin fluxus (“flow”).

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

Related words

Last updated June 20, 2026