1680s, in anatomy, "an interlacing of nerves, vessels, or fibers," Modern Latin, literally "braid, network," noun use of past participle of Latin plectere "to twine, braid, fold," from suffixed form of PIE root *plek- "to plait." Original use in solar plexus "network of nerves in the abdomen" (see solar). General sense of "net-like arrangement of parts" is from 1760s. Related: Plexal.
updated on July 11, 2020