Meaning of thoracic duct

thorac'ic duct'

Pronunciation: [key]
— Anat. Anat.
  1. the main trunk of the lymphatic system, passing along the spinal column in the thoracic cavity, and conveying a large amount of lymph and chyle into the venous circulation.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.