The Collaborative International Dictionary of English v.0.48:

Gnar \Gnar\, n. [OE. knarre, gnarre, akin to OD. knor, G.
   knorren. Cf. Knar, Knur, Gnarl.]
   A knot or gnarl in wood; hence, a tough, thickset man; --
   written also gnarr. [Archaic]
   [1913 Webster]

         He was . . . a thick gnarre.             --Chaucer.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Gnar \Gnar\, v. i. [imp. & p. p. Gnarred; p. pr. & vb. n.
   Gnarring.] [See Gnarl.]
   To gnarl; to snarl; to growl; -- written also gnarr.
   [Archaic]
   [1913 Webster]

         At them he gan to rear his bristles strong,
         And felly gnarre.                        --Spenser.
   [1913 Webster]

         A thousand wants
         Gnarr at the heels of men.               --Tennison.
   [1913 Webster]