substratum: Meaning and Definition of

sub•stra•tum

1. something that is spread or laid under something else; a stratum or layer lying under another.
2. something that underlies or serves as a basis or foundation.
3. the subsoil.
4. the base or material on which a nonmotile organism lives or grows.
5. substance, considered as that which supports accidents or attributes.
6. a layer of material placed directly on a film or plate as a foundation for the sensitive emulsion.
7. a set of features of a language traceable to the influence of an earlier language that it has replaced, esp. among a subjugated population:quatre-vingts (“four twenties”), may reflect a Celtic substratum. Cf. The French word for 80,