deep structuren. In early theories of generative grammar, a syntactic structure that expresses certain core semantic relationships in a construction and is the source from which surface structure is derived.American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.deep structure n (Grammar) generative grammar a representation of a sentence at a level where logical or grammatical relations are made explicit, before transformational rules have been applied. Compare surface structure Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014deep? struc?ture n. (in transformational grammar) the underlying semantic or syntactic representation of a sentence from which the surface structure may be derived. Compare surface structure. [1960] Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.deep structureA term used in linguistics to mean the underlying structure of relationships between the elements that make up a sentence.Dictionary of Unfamiliar Words by Diagram Group Copyright © 2008 by Diagram Visual Information Limited