The supporting part of a structure; the foundation.(noun)
The earth bank or bed supporting railroad tracks.(noun)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Use "substructure" in a sentence
"So the notion of substructure is sensitive to the choice of signature."
"It is known as the substructure of B generated by X, and we find it by first adding to X all the elements cB where c are individual constants of K, and then closing off under the functions"
"The substructure was a fine building, 148 feet by 78 feet; the vaulting was, as described by Professor Willis, "of the earliest kind; constructed of light tufa, having no transverse ribs, and retaining the impressions of the rough, boarded centring upon which they had been formed.""