A rodent quadruped, about two feet in length, of the family Castorid‘ and genus Castor, C fiber, at one time common in the northern regions of both hemispheres, now found in considerable numbers only in North America, but occurring solitary in central Europe and Asia, That piece of armor which protected the lower part of the face, whether forming a part of the helmet or fixed to the breastplate It was so constructed (with joints or otherwise) that the wearer could raise or lower it to eat and drink