flux

1 of 2

noun

ˈfləks 

1

: a flowing of fluid from the body: such as

a

: diarrhea

b

: dysentery

2

: a continuous moving on or passing by (as of a stream)

3

: a continued flow : flood

a flux of words

4

a

: influx

b

: change, fluctuation

in a state of flux

the flux following the death of the emperor

5

: a substance used to promote fusion (as of metals or minerals)

especially : one (such as rosin) applied to surfaces to be joined by soldering, brazing, or welding to clean and free them from oxide and promote their union

6

: the rate of transfer of fluid, particles, or energy across a given surface

flux

2 of 2

verb

fluxed; fluxing; fluxes

transitive verb

1

: to cause to become fluid

2

: to treat with a flux

intransitive verb

: to become fluid : fuse

Synonyms of flux

Noun

• fluctuation
• oscillation

Verb

• melt
• thaw

Examples of flux in a Sentence

Noun

the English language is always in a state of flux

January typically brings a great flux of returns to department stores.

Verb

a solid will flux more quickly under pressure

Recent Examples on the Web

Noun

Getty Images/iStockphoto Over the last few years, millions of Americans with federal student loans have been stuck navigating a system in flux. — Angelica Leicht, CBS News, 30 June 2026

Settings that are in constant flux or being adjusted too often are costly and have a higher risk of system failure. — Rae Ford, Martha Stewart, 27 June 2026

Verb

Then he was put on waivers by the Utah Mammoth in September and dealt to Edmonton in December, his career still flux. — Joe Smith, New York Times, 31 Jan. 2026

The technology uses the slag to combine it with fluxing agents. — Noël Fletcher, Forbes.com, 5 Sep. 2025

Word History

Etymology

Noun and Verb

Middle English, from Anglo-French & Medieval Latin; Anglo-French, from Medieval Latin fluxus, from Latin, flow, from fluere to flow — more at fluid

First Known Use

Noun

14th century, in the meaning defined at sense 1

Verb

15th century, in the meaning defined at transitive sense 1

Phrases Containing flux

• luminous flux
• magnetic flux
• radiant flux

Rhymes for flux

• chucks
• crux
• ducks
• dux
• klux
• lux
• plucks
• recce
• shucks
• sucks
• trucks
• tucks

Kids Definition

flux

1 of 2 noun

ˈfləks 

1

a

: a flowing in

flux of the tide

b

: a series of changes : a state of continuous change

2

: a substance used to aid the melting or joining (as by removing impurities) of metals or minerals

flux

2 of 2 verb

1

: to become or cause to become fluid : fuse

2

: to treat with a flux

Medical Definition

flux

noun

ˈfləks 

1

a

: a flowing or discharge of fluid from the body especially when excessive or abnormal: as

(1)

: diarrhea

(2)

: dysentery

b

: the matter discharged in a flux

2

: the rate of transfer of fluid, particles, or energy across a given surface