Burr (noun)

1. A rough, prickly envelope of a seed or fruit; a bur, as of a chestnut or acorn.
2. A rough, ragged edge or fringe remaining on a piece of material after it has been cut or torn.
3. A rough, rasping sound.
4. A small, projecting, often sharp edge or protuberance.
5. A raised area on a surface caused by a mechanical or chemical process.

Origin:

Middle english burre, from old english byrre.

Examples:

1. He had to take off his shirt and shake out the burrs that had stuck to the fabric.
2. The new saw left a burr on the edge of the wood.
3. He heard a burr in her voice when she spoke.
4. There's a burr on the edge of this coin.
5. The surface of the metal had a burr from the machining process.