IPA: /sʌbˈstrʌk.tʃər/
KK: /sʌbˈstrʌk.tʃɚ/
A part that supports a larger structure, often serving as its foundation or base.
The engineers examined the substructure to ensure it could support the new building.
Substructure → It is formed from "sub-" (meaning under) and "structura" (from Latin, meaning to build or arrange). The word "substructure" refers to the underlying structure or foundation that supports something above it.
Think of something that is built "under" ('sub-') another structure — that's why substructure means the foundation or underlying support.