Brush down Definition 1 of 2Pro Tip 1/3Cleaning Objects Primarily used when referring to cleaning items or surfaces with bristles to remove dirt. Remember to brush down your boots after hiking. Pro Tip 2/3Finishing Touch Used to describe the final step in grooming to give a neat appearance. After cutting his hair, the barber gave it a brush down. Pro Tip 3/3Post-Activity Often used after an activity that causes dirtiness, like walking or playing outside. She had to brush down her jacket after the campfire.