diffuser

noun

dif·​fus·​er di-ˈfyü-zər 

plural diffusers

1

: one that diffuses: such as

a

: a device (such as a reflector) for distributing the light of a lamp evenly

b

: a screen (as of cloth or frosted glass) for softening lighting (as in photography)

c

: a device (such as slats at different angles) for deflecting air from an outlet in various directions

d

: a device that produces a fine mist of water and often essential oils

2

: a device for reducing the velocity and increasing the static pressure of a fluid passing through a system

Examples of diffuser in a Sentence

Recent Examples on the Web

These include keeping cats confined to one quiet room during the packing and moving process, gradually introducing them to their new home, and using pheromone diffusers to reduce stress. —Lydia Patrick, MSNBC Newsweek, 3 Aug. 2025

The diffusers measure about 4 inches wide and 4 inches long. —Saleen Martin, USA Today, 29 July 2025

There is also a home fragrance line of candles, diffusers and room sprays, as well as a small amount of third-party products, but the assortment is overwhelmingly Martha Stewart. —David Moin, Footwear News, 25 July 2025

The hot-swappable switches used in the Flow 2 include high-quality diffusers that improve the transmission of light from the white LED backlights on each switch. —Mark Sparrow, Forbes.com, 11 July 2025

Word History

Etymology

diffuse entry 2 + -er entry 2

First Known Use

1645, in the meaning defined at sense 1

Rhymes for diffuser

• abuser
• accuser
• boozer
• bruiser
• chooser
• cruiser
• loser
• user
• multiuser