Burr/bɜːr/ Definition 1 of 5Pro Tip 1/2Unwanted Residue After manual or machine work, tiny unwanted bits that stick out are called 'burrs'. I spent an hour sanding off all the burrs from the handrail. Pro Tip 2/2Careful Handling 'Burr' often implies the item may cause injury or damage if not removed. Be careful with that metal sheet; it has sharp burrs.