Webster’s Revised Unabridged Dictionary · 1913
Gnarl
Gnarl (närl), v. i. [imp. & p. p. Gnarled; p. pr. & vb. n. Gnarling.] [From older gnar, prob. of imitative origin; cf. G. knarren, knurren. D. knorren, Sw. knorra, Dan. knurre.] To growl; to snarl.
And wolves are gnarling who shall gnaw thee first. Shak.
Gnarl, n. [See Gnar, n.] a knot in wood; a large or hard knot, or a protuberance with twisted grain, on a tree.