diffuser

or dif·fu·sor

[ dih-fyoo-zer ]

noun

1. a person or thing that diffuses.
2. (in various machines or mechanical systems, as centrifugal pumps or compressors) a device for utilizing part of the kinetic energy of a fluid passing through a machine by gradually increasing the cross-sectional area of the channel or chamber through which it flows so as to decrease its speed and increase its pressure.
3. (in a lighting fixture) any of a variety of translucent materials for filtering glare from the light source.
4. a pierced plate or similar device for distributing compressed air for aeration of sewage.

diffuser

/ dɪˈfjuːzə /

noun

1. a person or thing that diffuses
2. a part of a lighting fixture consisting of a translucent or frosted covering or of a rough reflector: used to scatter the light and prevent glare
3. a cone, wedge, or baffle placed in front of the diaphragm of a loudspeaker to diffuse the sound waves
4. a duct, esp in a wind tunnel or jet engine, that widens gradually in the direction of flow to reduce the speed and increase the pressure of the air or fluid
5. photog a light-scattering medium, such as a screen of fine fabric, placed in the path of a source of light to reduce the sharpness of shadows and thus soften the lighting
6. a perforated plate or similar device for distributing compressed air in the aeration of sewage
7. a device, attached to a hairdryer, which diffuses the warm air as it comes out

Word History and Origins

Origin of diffuser¹

First recorded in 1670–80; diffuse + -er ¹

Example Sentences

It offers 4 speed settings for sufficient cooling, along with a built-in diffuser that provides a fine mist and spreads the scent of essential oils.

From Popular-Science

Once the liquid reaches the top, it hits a diffuser that causes the fluid to splash down, creating an internal shower.

From Outside Online

An internal shock mount, sound diffuser, and other proprietary tech automatically reduce noise, so you’ll sound as good as the Lyra looks.

From Popular-Science

The best hair dryer overall for curly hair will be equipped with ionic capabilities, multiple heat settings, diffuser attachment, and a cold shot button to seal in shine after hair has dried.

From Popular-Science

Many will also come with a diffuser attachment or concentrator nozzle, but there is definitely room to expand.

From Popular-Science

It seems probable that he was a diffuser of knowledge rather than an originator, but as a great teacher his fame is secure.

From Project Gutenberg

Here is an example of Spenser's diffuser style, taken from the second book of the Faerie Queene.

From Project Gutenberg

The old idea of a librarian was that of a guardian or keeper of books—not a diffuser of knowledge, but a mere custodian of it.

From Project Gutenberg

The most conspicuous addition made by Mr. Boyden was the diffuser.

From Project Gutenberg

Fix the charcoal well with a spray diffuser and the usual solution of white shellac in spirits of wine.

From Project Gutenberg