Dictionary.com
definitions

subependymoma

[sŭb′ĭ-pĕn′də-mō′mə]
n.
  1. An ependymoma in which there are discrete, lobulated nodules in the walls of the anterior third or posterior fourth ventricles of the brain.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.