Dust is read as neglect and time passing — things left untouched for too long. Brushing it away traditionally stands for reviving an old interest or relationship.
Does the traditional reading fit your dream, or did it mean something else to you?
My Cosmic Code has a private dream journal. Write a dream down and the app picks out the symbols in it, shows what dream books say about them and, over time, which words recur across your entries. The journal is stored on your device only.