Superstructure
WordNet
noun
(1) Structure consisting of the part of a ship above the main deck
WiktionaryText
Noun
- Any structure built above the top full deck. (FM 55-501).
- Any material structure or edifice built on something else; that which is raised on a foundation or basis
- all that part of a building above the basement. Also used figuratively.
- (railroad) The sleepers, and fastenings, in distinction from the roadbed.