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

Instead, Rousell recommends a more subtle approach, like an essential oil diffuser that uses natural fragrances believed to boost focus and mood, such as lavender, citrus, and rosemary. —Patricia Shannon, Better Homes & Gardens, 4 Mar. 2026

The front splitter, coupled with the front diffuser and wheel arch diffusers, increases downforce to improve handling on curves and set better lap times, the marque says. —Erik Shilling, Robb Report, 2 Mar. 2026

The 12-ounce candles with 60 hour burn time, 7-ounce diffusers, 30-milliliter room spray and 15-milliliter roll-on perfume available in both scents. —Tory Johnson, ABC News, 27 Feb. 2026

This diffuser uses warmth to fill a room and release calming pheromones to help with your pup's anxiety. —Jessica Moore, USA Today, 27 Feb. 2026

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