Definition of Interventricular septum

Interventricular septum: The stout wall that separates the lower chambers (the ventricles) of the heart from one another. A hole in the interventricular septum is termed a ventricular septal defect (VSD).

Source: MedTerms™ Medical Dictionary
http://www.medterms.com/script/main/art.asp?articlekey=4002
Last Editorial Review: 3/19/2012