[f. SUB- 3 + STRUCTURE, after prec.] Arch. That part of a building which supports the superstructure; an under-structure, substruction.
1726. Leoni, Alberti’s Archit., I. 48/1. These … Stones must be … link’d with the under Courses, so as to make a kind of pavement at top to … protect the Substructure.
1840. Longf., Skel. Arm., Introd. The substructure of a windmill.
1861. Beresf. Hope, Eng. Cathedr. 19th C., 89. The moderate scantlings … obviate the risk of the roof crushing down the substructure.
1876. Encycl. Brit., IV. 284/1. The substructure of a bridge consists of foundations, abutments, and piers.
1884. Manch. Exam., 19 Dec., 5/3. The sub-structure of the pier.
b. transf. and fig.
1735. S. Harris, Comm. 53rd Ch. Isa., Pref. 16. A substructure of their chronology, geography, and history.
1851. Jrnl. Asiat. Soc. Bengal, 7. The kingdom of Menes … rests upon a venerable substructure of several centuries of the Nile valley.
1856. Kane, Arctic Expl., II. xxvii. 271. This glacier … sloped gradually upward … and then, following the irregularities of its rocky sub-structure, suddenly became a steep crevassed hill.
1875. E. White, Life in Christ, I. viii. (1878), 73. No decisive anticipation of immortality for mankind as a substructure for religious faith can be deduced.
Hence Substructural a., of the nature of a substructure.
1866. Pall Mall Gaz., 12 May, 12. A narrative of long public services, mostly underground and substructural.
1884. Homilet. Monthly, Sept., 684. These are the substructural truths of revelation.
