RhymeZone: knurl definitions

Definitions of knurl:

noun: A contorted knot in wood.
noun: A crossgrained protuberance; a nodule; a boss or projection.
noun: A lined or crossgrained pattern of ridges or indentations rolled or pressed into a part for grip.
verb: To roll or press a pattern of ridges or indentations into a part for grip.

(Definitions from Wiktionary)