Plexus \Plex"us\, n.; pl. L. {Plexus}, E. {Plexuses}. [L., a
twining, braid, fr. plectere, plexum, to twine, braid.]
1. (Anat.) A network of vessels, nerves, or fibers.

2. (Math.) The system of equations required for the complete
expression of the relations which exist between a set of
quantities. --Brande & C.

3. A network; an intricate or interwoven combination of
elements or parts in a coherent structure.

In the perception of a tree the reference to an
object is circumscribed and directed by a plexus of
visual and other presentations. --G. F. Stout.
[Webster 1913 Suppl.]