knurl

/N ER1 L/
noun
  1. 1

    A contorted knot in wood.

  2. 2

    A crossgrained protuberance; a nodule; a boss or projection.

  3. 3

    A lined or crossgrained pattern of ridges or indentations rolled or pressed into a part for grip.

verb
  1. 1

    To roll or press a pattern of ridges or indentations into a part for grip.

Source: https://en.wiktionary.org/wiki/knurl