What Does “In Flux” Mean?

In flux is an expression meaning fluid, not fixed, or given to change at any moment. Although English speakers have co-opted it into the vernacular, you might be surprised to learn that its origin does not even derive from English. It can also be used in a number of different contexts, as we’ll explain below.

An ancient tradition

So what is flux? The term comes from Latin, a form of the verb fluere, which means “to flow.” This linguistic origin evokes the idea of a river, constantly in motion and never staying the same. Therefore the definition is very literal: something that is in flux (or in-flux, although usually, the hyphen is unnecessary) is flowing in and out, sometimes at a greater intensity and sometimes at a lesser one, and it never stays in one position or amount for long.

Similarly, to have an influx of something (the noun, as opposed to the verb of being in flux) is to experience a sudden growth or surge in it.

Example

We’ve had an influx in clicks on our website thanks to the new ad we put out yesterday.

Context and usage

How would you use “in flux” in daily life? Well, in addition to suggesting fluidity and flexibility, the term itself is fluid enough to apply to a range of situations, both literal and metaphorical.

Examples

My income has been in flux from month to month ever since I became a freelancer.

Her friendships are usually in flux because she moves cities so often.

The hospital has had an influx in the number of flu patients.

The business is still so young that its budget is always in flux.

Example of using “in flux” idiom