English Reference

Word

flux

US/ˈfɫəks/

UK/flˈʌks/

Definitions

01constant change

B2

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

n. a state of continuous change, instability, or fluctuation.

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

“The political landscape remained in constant flux as shifting alliances made it impossible to predict the outcome of the upcoming vote.”

Antonyms

02energy transfer

C1 · Science

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

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

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

“Calculating the radiant flux is essential for determining how much solar energy actually reaches the surface of the planet.”

Technical

Synonyms

03metal cleaning agent

C1 · Technical

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

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

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

“Without the application of a high-quality flux, the solder will fail to adhere to the oxidized copper pipes.”

Technical

Synonyms

cleanerpurifier

04bodily discharge

C2 · Medicine

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

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

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

“Historical accounts of the siege mention that more men succumbed to the flux than to actual combat injuries.”

Archaic

05to melt

C2 · Science

v. to make something become liquid using heat.

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

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

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

Technical

Synonyms

meltfuseliquefy

Antonyms

Real-World Examples

“It is a club in a state of flux, lacking certainty on and off the pitch.”
The Guardian · 16 Aug 2026
“Howe’s departure, and the loss of those big names, has returned Newcastle to the state of flux that was long their usual state of existence.”
The Guardian · 12 Aug 2026

Etymology

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

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

Related words

Domain

Physics

This entry

Level
C1 · Advanced
Frequency
Frequent
Updated

Scan code

englishreference.com/q/flux

English Reference