Definition of "knurl"

noun:
- A contorted knot in wood.
  
  from Wiktionary, Creative Commons Attribution/Share-Alike License
- A crossgrained protuberance; a nodule; a boss or projection.
  
  from Wiktionary, Creative Commons Attribution/Share-Alike License
- A lined or crossgrained pattern of ridges or indentations rolled or pressed into a part for grip.
  
  from Wiktionary, Creative Commons Attribution/Share-Alike License
verb:
- To roll or press a pattern of ridges or indentations into a part for grip.
  
  from Wiktionary, Creative Commons Attribution/Share-Alike License