n :  a condition characterized by elevated venous pressure of the upper extremities with accompanying distension of the affected veins and swelling of the face and neck and caused by blockage (as by a thrombus or an aneurysm) or compression (as by a neoplasm) of the superior vena cava .
 
 
 
Published under license with Merriam-Webster, Incorporated.  © 1997-2024.