Webster's Revised Unabridged Dictionary · 1913

Grizzle

Grizzle , noun

[French gris: compare grisaille hair partly gray, from gris gray. See Gris, and compare Grisaille.]

Gray; a gray color; a mixture of white and black. — Shakespeare

Grizzle , verb, transitive and intransitive

To make or become grizzly, or grayish.
Hardship of the way such as would grizzle little children. — R. F. Burton
I found myself on the Nubian desert shaking hands with a grizzling man whom men addressed as Collins Bey. — Pall Mall Mag

Grizzle , verb, intransitive and transitive

[Etym. uncertain.]

To worry; to fret; to bother; grumble. [Provincial English]
Don't sit grizzling there. — Charles Reade