substrate

1. An underlying layer; a substratum.
2. The substance lining the bottom edge of an enclosure. · The substrate of an aquarium can affect the water's acidity.· Stream substrate affects fish longevity.
3. A substance acted upon, as by an enzyme.
4. A surface on which an organism grows, or to which an organism or an item is attached. · The rock surface of a rockpool is the substrate for a sessile organism such as a limpet.
5. A language that is replaced in a population by another language and that influences the language imposed on its speakers.
6. A metal which is plated with another metal which has different physical properties.
7. A surface to which a substance adheres.

الجمع substrates