n., pl., -di·a (-dē-ə).
An organ or a part in its most rudimentary form or stage of development.
[Latin prīmōrdium. See primordial.]
The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.
