RhymeZone: mystacial definitions

Definitions of mystacial:

adjective: Having a fringe of hairs suggestive of a moustache.
adjective: Pertaining to the area around the vibrissae on either side of the muzzle of a mammal such as a rodent or cat.
noun: Any of the large rigid whiskers (vibrissae) that appear on the fleshy pads on either side of the muzzle of an animal such as a cat or rodent.

(Definitions from Wiktionary)