Byssus

1. n. Asbestus.
2. n. A cloth of exceedingly fine texture, used by the ancients. It is disputed whether it was of cotton, linen, or silk.
3. n. 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.
4. n. An obsolete name for certain fungi composed of slender threads.

The word meanings were obtained from OPTED(The Online Plain Text English Dictionary), which is based on “The Project Gutenberg Etext of Webster’s Unabridged Dictionary” which is in turn based on the 1913 US Webster’s Unabridged Dictionary (See Project Gutenburg), as a text file.