diffuser

American  

[dih-fyoo-zer] / dɪˈfyu zər /

Or diffusor

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.

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diffuser British  

/ 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

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Etymology

Origin of diffuser

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

Example Sentences

Smith likes the Porseme 500-Milliliter Oil Diffuser, which can emit aromas for up to 21 hours, depending on the setting.

From Seattle Times • Dec. 20, 2021

Vitruvi Move Diffuser: The newest electric essential-oil diffuser from this Vancouver, B.C., company is conveniently cordless.

From Seattle Times • Nov. 10, 2021

A little pricey, but the Petal Diffuser works well and is nice to look at.

From Slate • Mar. 31, 2018

If you’re all about the looks, an architect out in California told us that all of her colleagues are particularly enamored with Muji’s Ultrasonic Aroma Diffuser, which they just use as humidifiers.

From Slate • Jan. 31, 2018

Firing Head A. Diffuser and choke ring clearance not uniform B. Diffuser and choke ring face dimension out of tolerance.

From Installation and Operation Instructions For Custom Mark III CP Series Oil Fired Unit by Anonymous