plexus

noun3

1. •
   A network of anastomosing or interwoven nerves, blood vessels, or lymphatic vessels.
2. •
   An interwoven combination of parts or elements in a structure or system.

   • I have the sensation of being immersed in the very plexus of life, focal from whatever place, position or attitude I take my stance. — 1934
3. •
   The system of equations required for the complete expression of the relations which exist between a set of quantities.

   • Plexus (Lat.). The system of equations required for the complete expression of the relations which exist between a set of quantities. — 1866