What does "byssus" mean?

Byssus: (Zoöl.) 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.

Additional senses

  1. 2.(Bot.) An obsolete name for certain fungi composed of slender threads.
  2. 3.Asbestus.

Sources