knurl

or nurl

[ nurl ]
/ nɜrl /

noun

a small ridge or bead, especially one of a series, as on a button for decoration or on the edge of a thumbscrew to assist in obtaining a firm grip.
a knur.

verb (used with object)

to make knurls or ridges on.

Origin of knurl

1600–10; earlier knurle (noun). See knur, -le

British Dictionary definitions for knurl

knurl

nurl

/ (nɜːl) /

verb (tr)

to impress with a series of fine ridges or serrations

noun

a small ridge, esp one of a series providing a rough surface that can be gripped

Word Origin for knurl

C17: probably from knur