substructure

Etymology
From.

Noun

 * 1) The supporting part of a structure (either physical or organizational; the foundation).
 * 2) The earth or gravel that the railway tracks are embedded in.
 * 1) The earth or gravel that the railway tracks are embedded in.

Translations

 * Bulgarian: ,
 * Czech: spodní stavba, železniční spodek
 * Finnish:
 * French:
 * Irish: fostruchtúr
 * Latin: substructiō
 * Romanian:
 * Spanish: subestructura

Etymology
From.