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

Adaptive underbody front diffusers direct air to minimize drag or increase engine cooling, as needed. —Mark Phelan, USA Today, 7 Sep. 2025

Finally, after months of trials using different numbers and types of LEDs in a range of layouts and with different light diffusers, the team had a breakthrough. —Mark Sparrow, Forbes.com, 7 Sep. 2025

Adaptive underbody front diffusers direct air to minimize drag or increase engine cooling, as needed. —Mark Phelan, Freep.com, 4 Sep. 2025

The device can also double as an aromatherapy diffuser when paired with your choice of essential oil. —Maggie Horton, People.com, 3 Sep. 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