Definition of byssus in US English:


nounPlural byssuses, Plural byssi

  • 1historical A fine textile fiber and fabric of flax.

    • ‘If we understand it of thread, it may refer to the byssus or fine flax for which Egypt was famous; but I do not see on what authority we translate it linen thread.’
    • ‘The word denotes Egyptian linen of peculiar whiteness and fineness (byssus).’
    • ‘Linen fabrics (Byssus) were as marketable in China as were silk fabrics in the west.’
    • ‘Exactly how these proteins link together to give the material, called byssus, its strength has remained unclear.’
  • 2Zoology
    A tuft of tough silky filaments by which mussels and some other bivalves adhere to rocks and other objects.

    as modifier ‘byssus threads’
    • ‘The individual cages allowed the transfer of mussels to respirometry chambers without severing their byssus.’
    • ‘The primary source of this variation is not the number of threads present in the byssus, but rather, their thickness.’
    • ‘By the time the shells are mature, they have lost the byssus anchor and are found loose on the ocean floor.’
    • ‘The strength of the entire byssus is expected to be proportional to the number of threads times the average strength of each thread.’
    • ‘Before serving them to the knots, we put the mussels through a mesh to break the byssus threads that held them together and to sort them by size.’
    clump, bunch, knot, cluster, tussock, tuffet
    View synonyms


Late Middle English: from Latin, from Greek bussos, of Semitic origin.