Dictionary.com
definitions

diffuser

or dif·fu·sor

[dih-fyoo-zer]
|

noun

a person or thing that diffuses.
(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.
(in a lighting fixture) any of a variety of translucent materials for filtering glare from the light source.
a pierced plate or similar device for distributing compressed air for aeration of sewage.

Origin of diffuser

First recorded in 1670–80; diffuse + -er1
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for diffuser

Historical Examples of diffuser

  • Never fear that you can be too prolix: the diffuser you are, the easier I shall forgive myself.

    The Disowned, Complete

    Edward Bulwer-Lytton

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

  • 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.

    A Book for All Readers

    Ainsworth Rand Spofford

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

    Milton

    Sir Walter Alexander Raleigh

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

British Dictionary definitions for diffuser

diffuser

diffusor

noun

a person or thing that diffuses
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
a cone, wedge, or baffle placed in front of the diaphragm of a loudspeaker to diffuse the sound waves
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
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
a perforated plate or similar device for distributing compressed air in the aeration of sewage
a device, attached to a hairdryer, which diffuses the warm air as it comes out
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012