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

On the other side of the debate are diffusers, who emphasize that victory in the AI race depends on other countries adopting and running on American compute, cloud, and agent tools. —Daniel Benaim, Foreign Affairs, 9 Dec. 2025

Humidifiers and diffusers aren’t the same thing. —Kamron Sanders, Better Homes & Gardens, 9 Dec. 2025

Best Amazon Prime Black Friday Home Deals Amazon Prime members can unlock a ton of great Black Friday deals in the home department, including a lightweight and nimble cordless stick vacuum and an essential oil diffuser that would make an excellent gift this holiday season. —Clara McMahon, PEOPLE, 28 Nov. 2025

Complete with four attachments—a concentrator, diffuser, brush, and finisher—this do-it-all hair dryer is the next best thing to a cosmetology school diploma. —Annie Blackman, Allure, 26 Nov. 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