Greymuzzle is a term for someone who has been involved in the therian community for a long time (usually at least 10 years or more) or is 30 plus years of age, or has garnered widespread respect in the community and is seen as an "elder". (note though, the therian community has no leaders, only people who are more respected) Some examples of Greymuzzles are Wolf VanZandt, who is really old, and Coyote who founded werelist long long ago.
Greymuzzle was first used on AHWW. They are the 'backbones' of the community who had been in the group the longest." (citation needed)