"Dust down" is a commonly used phrase that refers to the act of cleaning off dirt and debris that has settled on an object, surface, or area. However, there are several other synonyms that can be used in place of "dust down" to convey the same meaning. Some examples include "brush off," "sweep away," "wipe clean," "dust off," "clean off," and "polish up." Each of these phrases can be used depending on the context and situation, and can help add variety and nuance to one's vocabulary. Using synonyms is an effective way to avoid repetition and keep language interesting and engaging.