grizzliest
grizz-li-est
adjective
Most grey-haired or most inclined to complain and be irritable.
"He was the grizzliest old man in the queue."
Thesaurus
Synonyms: old, grey, white-haired, hoary, grey-headed, grizzly, gray-haired, gray-headed, hoar, grey-haired, gray, silvertip