Su`per*struc"ture (?), n. [Cf. F. superstructure.]
Any material structure or edifice built on something else; that which is raised on a foundation or basis
; esp. Arch.
all that part of a building above the basement. Also used figuratively.
You have added to your natural endowments the superstructure of study.
2. Railway Engin.
The sleepers, and fastenings, in distinction from the roadbed.
© Webster 1913.