immediate constituent definition by Webster's New World
Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio. Used by arrangement with John Wiley & Sons, Inc.
any of the meaningful hierarchical components into which a complex linguistic structure may be directly divided and which may in turn be subdivided
immediate constituent definition by American Heritage Dictionary
A meaningful constituent, such as a word, that enters directly into the formation of a linguistic construction, such as a phrase.