WordWeight : Weighing the Words

Pronunciation : Sub*stra"tum
Part of Speech : n.;
Etymology : [L. substratus, p.p. of substernere to strew under; sub under + sternere to strew. See Stratum.]
Definition : 1. That which is laid or spread under; that which underlies something, as a layer of earth lying under another; specifically (Agric.), the subsoil.

2. (Metaph.)

Defn: The permanent subject of qualities or cause of phenomena; substance.

pl. Substrata.
Source : Webster's Unabridged Dictionary, 1913