noun.
In histology, a delicate fiber, such as, according to one theory, is found in the protoplasm of cells.
noun.
A small fiber; a fibrilla; a filament.
noun.
Specifically In botany: One of the delicate cottony hairs or thread-like growths found upon the young rootlets of some plants.
noun.
A rootlet of a lichen.
noun.
One of the filaments which line the utricles of Sphagnum.
noun.
The stipe of some fungi: in this sense disused.