What is Dust ?
Dust is (noun) a thin layer of dry dirt The room had never been cleaned there was dust everywhere. A tiny speck of dust got in my eye. Synonym powder (NOTE: no plural) (verb) 1. to remove dust from something Don’t forget to dust the Chinese bowls carefully. 2. to sprinkle a powder on something She dusted the cake with icing sugar.
source: Easier English, Student Dictionary Upper Intermediate Level