Green’s Dictionary of Slang

1. (also grizzlepate) a grumbler, a whinger.

1699		N. Ward London Spy IX 203: The Cobler being an Old Sturdy Grizzle, the fellow was forc’d to bear both with this Correction and Reproof.
1797		M. Robinson Walsingham II 161: ‘Sport your glass-blinkers, old grizzlepate,’ cried the inebriated prisoner.
1815		‘Comical Tragedy of Little Tom Thumb’ Sailor’s Vocal Repository 12: Old Grizzle, a lord, [...] for love got drunk as a sow, sir.

2. a fit of whingeing, grumbling or sulking, a peevish mood.

1908

A.N. Lyons Arthur’s 12: At first I thought she was goin’ to do a grizzle, but she turned round quick, with a kind of smile.