something that is spread or laid under something else; a stratum or layer lying under another.
something that underlies or serves as a basis or foundation.
Agriculture. the subsoil.
Biology. the base or material on which a nonmotile organism lives or grows.
Philosophy. substance, considered as that which supports accidents or attributes.
Photography. a layer of material placed directly on a film or plate as a foundation for the sensitive emulsion.
Historical Linguistics. a set of features of a language traceable to the influence of an earlier language that it has replaced, especially among a subjugated population: The French word for 80, quatre-vingts (“four twenties”), may reflect a Celtic substratum.
the nonliving material on which an animal or plant grows or lives
a. the solid rock underlying soils, gravels, etc; bedrock
b. the surface to which a fixed organism is attached
sociol any of several subdivisions or grades within a stratum
photog Sometimes shortened to: sub a binding layer by which an emulsion is made to adhere to a glass or film base
philosophy substance considered as that in which attributes and accidents inhere
linguistics Compare superstratum the language of an indigenous population when replaced by the language of a conquering or colonizing population, esp as it influences the form of the dominant language or of any mixed languages arising from their contact
[C17: from New Latin, from Latin substrātus strewn beneath, from substernere to spread under, from sub- + sternere to spread]