plexus thyroideus impar

n.
  1. A venous plexus located in front of the lower portion of the trachea, forms from anastomoses between the inferior thyroid veins, and terminates in the inferior thyroid vein.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.