Learner's definition of BURR
a rough covering of a nut or seed
◊ Burrs often have small hooks that stick to clothing and fur.
a rough area on a piece of metal that is left after the metal is cut
a strong way of pronouncing r that is used by some speakers of English especially in northern England and in Scotland
— usually singular
a burr in/under the saddle
someone or something that is a constant cause of trouble or annoyance