/nerrl/ , n.
1. a small ridge or bead, esp. one of a series, as on a button for decoration or on the edge of a thumbscrew to assist in obtaining a firm grip.
2. a knur.
v.t.
3. to make knurls or ridges on.
Also, nurl .
[ 1600-10; earlier knurle (n.). See KNUR, -LE ]