ETYM Old Eng. burre burdock; cf. Dan. borre, OSw. borra, burdock, thistle; perh. akin to Eng. bristle (burr- for burz-), or perh. to French bourre hair, wool, stuff.
1. Small bit used in dentistry or surgery; SYN. burr.
2. A thin ridge or area of roughness produced in cutting or shaping metal.
3. An irregular rounded mass; especially; a tree burl.

Seed vessel having hooks or prickles; SYN. burr.
Or burr; In botany, a type of “false fruit” or pseudocarp, surrounded by numerous hooks; for instance, that of burdock Arctium, where the hooks are formed from bracts surrounding the flowerhead. Burs catch in the feathers or fur of passing animals, and thus may be dispersed over considerable distances.
The term is also used to include any type of fruit or seed with hooks, such as that of sandbur Cenchrus, a grass, and white avens Geum canadese.

To remove the burrs from; SYN. burr.