Is there a single word used in English for the visibility of dust particles floating in a stream of sunlight?

real particles of dust in a sunbeam from the window

  • 14
    They are called "motes."
    – deadrat
    Commented Jun 18, 2015 at 20:33
  • 2
    I don't mean they actual particles themselves; I am referring to the phenomenon as a whole.
    – Jessica
    Commented Jun 18, 2015 at 20:35
  • I wasn't very helpful, was I? Sorry. I can't think of a noun, just adjectives. For an atmospheric phenomenon, "crepuscular rays." For general optics,"volumetric lighting." I hope that's better.
    – deadrat
    Commented Jun 18, 2015 at 20:50
  • I was hoping for something more specific to seeing the small individual dust motes floating. Perhaps there is no such word. You have all been very helpful, thank you.
    – Jessica
    Commented Jun 18, 2015 at 20:51
  • See this related question
    – bib
    Commented Jun 18, 2015 at 22:47

7 Answers 7


There is an uncommon word, dustlight, mainly appearing in literary works. It may serve as a single word for the whole phenomenon to describe the interplay between dust and light.

...there was no alternative but to count the remnant of the family savings in the feeable ray of moted dustlight that filtered down from the dingy opening.

The Possession of Immanuel Wolf: And Other Improbable Tales by Marvin Kaye

Beyond the dogs, the bottle, the old man, I saw santuario receding from view, glazed as it were by the scrim of dustlight.

Trinity Fields by Bradford Morrow

However, you can use mote to define the floating dust in sunlight:

A particle of dust, esp. one of the innumerable minute specks seen floating in a beam of light; (contextually) an irritating particle in the eye or throat. [OED]

An example from OED:

Moving freely about like the motes we see in the sunbeam.

1880, W. Wallace, Epicureanism

Scientifically, the phenomenon is light scattering.

You can check further details in the following links:


The most widely-used technical term is 'scatter', and this is studied in Physics (Light), Astronomy, Meteorology and Hydraulics (measurement of flow). (click @ermanen's link)

Many authors say 'scintillate', for the light-effect, but always 'motes' are mentioned; so, scintillation by itself might not work.

Home By Marilynne Robinson
A few motes of straw managed to scintillate in any shaft of sunlight.


"Moted". As in, "The moted light" etc.

The definition from Lexico:

Of light: full of motes.

  • By the definition, this sounds exactly like what the OP wants. But it just does not sound good. 'Mote' is very old-fashioned and 'moted' barely recognizable.
    – Mitch
    Commented Oct 20, 2021 at 16:04

You could, circumstances being appropriate, call the dust murk. Though it'd have to be sun shining into an otherwise gloomy place. And it's not specifically the sun-illuminated dust, but all the dust.

An adjective for the air is turbid, in that it has suspended particles.

motes/sunbeam/Tyndall effect are all more appropriate given the photo. Just adding some more terms in the event someone's not satisfied with the more straightforward words.


Consider, skylight

The diffuse light from the sky, scattered by air molecules, as distinguished from the direct radiation from the sun.

Random House



Tyndall effect, also called Tyndall phenomenon, scattering of a beam of light by a medium containing small suspended particles—e.g., smoke or dust in a room, which makes visible a light beam entering a window. The effect is named for the 19th-century British physicist John Tyndall, who first studied it extensively.

  • Related, but doesn’t answer the actual question.
    – Jim
    Commented Dec 6, 2020 at 3:13

It's called a colloid! It's a chemical term that means evenly dispersed particles in gas solid or liquid.

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