byssus (noun; plural
byssi,
byssuses; Latin
byssos, fine flax): 1. (
Mollusca:
Bivalvia) Fibers or small bundles of silky threads by which they anchor themselves to the substratum; beard.
2. (NEMATA: Adenophorea) A series of elaborately branched projections at the poles of mermithid eggs, by which they attach to plants.