·noun Asbestus.
II. Byssus ·noun An obsolete name for certain fungi composed of slender threads.
III. Byssus ·noun A cloth of exceedingly fine texture, used by the ancients. It is disputed whether it was of cotton, linen, or silk.
IV. Byssus ·noun A tuft of long, tough filaments which are formed in a groove of the foot, and issue from between the valves of certain bivalve mollusks, as the Pinna and Mytilus, by which they attach themselves to rocks, ·etc.