- infrastructure, substructure - the basic structure or features of a system or organization
--1 is a kind of structure
--1 is a part of system - foundation, base, fundament, foot, groundwork, substructure, understructure - lowest support of a structure; "it was built on a base of solid rock"; "he stood at the foot of the tower"
--2 is a kind of support
--2 is a part of structure, construction
--2 has particulars: bed; raft foundation