1
: fine dry powder that builds up inside buildings on surfaces that have not recently been cleaned
The floor was covered with dust.
You can see the dust particles floating through the air.
There is not a speck of dust in that house.
Note: Something that is collecting/gathering dust is not being used.
2
: fine powder made up of very small pieces of earth or sand
As the car sped down the dirt road, it left a cloud of dust behind.
The wind kicked up dust. [=blew dust into the air]
3
: fine powder made from a particular substance
coal/gold dust
He wiped the chalk dust off his hands.
dusts; dusted; dusting
1
: to make (something) clean by brushing or wiping dirt and dust from the surface
He dusted the furniture.
—often + off or downShe dusted the sand off her leg.
(US) He stood up and dusted himself off. = (Brit) He stood up and dusted himself down. [=he brushed the dirt/dust off his clothes]
I dust at least once a week.
2
: to cover (something) with a fine powder
Dust the pan with flour.
The police dusted the table for fingerprints. [=they put a fine powder on the table so that any fingerprints could be seen]
The crops will be dusted with pesticide.
Cite this Entry
“Dust.” Merriam-Webster.com Simple Definition, Merriam-Webster, https://www.merriam-webster.com/simple/dust. Accessed 19 Jun. 2026.
Copy Citation
