plexus

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A structure in the form of a network, especially of nerves, blood vessels, or lymphatics.
• noun A combination of interlaced parts; a network.

from The Century Dictionary.

• noun In botany, the mass of branched and anastomosing filaments of certain algæ.
• noun In physical geography, the irregular and complicated junction of a number of similar features, such as ridges, river channels, etc.
• noun A network; any collection of intimately coherent parts, as of an argument.
• noun In anatomy, an interlacing of nerves, vessels, or fibers; a net-like arrangement of parts, or the parts so disposed: especially said of certain delicate vascular membranes chiefly composed of minute anastomosing blood-vessels, as the choroid plexus, and of similar arrangements of nerves of the spinal and sympathetic systems.
• noun In mathematics, a system of one-fold relations.
• noun The continuation of the prostatic plexus, supplying the erectile tissue of the penis. Also called cavernous nerves.
• noun Same as gastric plexus .
• noun A secondary plexus of the cæliac, accompanying the gastric artery. Also called coronary plexus.
• noun A large and copiously anastomosing network of veins in the lower wall of the rectum, beneath the mucous coat, from which the hemorrhoidal veins proceed.
• noun A plexus of veins surrounding the base of the prostate, formed mainly from the dorsal veins of the penis.
• noun The lower section of the sacral plexus .
• noun A plexus of veins in the back of the pelvis, tributary to the middle sacral vein.
• noun Same as pampiniform plexus.
• noun Venous channels at the sides of the uterus, and in the broad ligaments, emptying into the ovarian veins.
• noun A plexus derived from the pelvic plexus, distributed to the lower part and side of the bladder, the prostate, and the seminal vesicle.

from the GNU version of the Collaborative International Dictionary of English.

• noun (Anat.) A network of vessels, nerves, or fibers.
• noun (Math.) The system of equations required for the complete expression of the relations which exist between a set of quantities.
• noun A network; an intricate or interwoven combination of elements or parts in a coherent structure.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A network or interwoven mass, especially (anatomy) of nerves, blood vessels, or lymphatic vessels.
• noun mathematics The system of equations required for the complete expression of the relations which exist between a set of quantities.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a network of intersecting blood vessels or intersecting nerves or intersecting lymph vessels