[syn: foundation, base, fundament, foot, groundwork, substructure, understructure]
The Collaborative International Dictionary of English v.0.48:
Substructure \Sub*struc"ture\, n. [Pref. sub- + structure.]
1. (Arch.) Same as Substruction.
[1913 Webster]
2. An under structure; a foundation; groundwork.
[1913 Webster]
WordNet (r) 3.0 (2006):
substructure
n 1: the basic structure or features of a system or organization
[syn: infrastructure, substructure]
2: lowest support of a structure; "it was built on a base of
solid rock"; "he stood at the foot of the tower" [syn:
foundation, base, fundament, foot, groundwork,
substructure, understructure]