/ Dictionary / Index P plexus: Meaning and Definition of Find definitions for: plex•us Pronunciation: (plek'sus), [key] — pl. -us•es, -us. a network, as of nerves or blood vessels. any complex structure containing an intricate network of parts: the plexus of international relations. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: plexus (Thesaurus) plexor Pleyel Related Content Daily Word Quiz: mamba Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language