substrate

noun ! Definition from WordNet 3.1, Princeton University. Pronunciation from Wiktionary, via Kaikki.org. More about substrate at Wordnik → Where our words come from →

1. The substance that is acted upon by an enzyme or ferment.
2. A surface on which an organism grows or is attached.

   the gardener talked about the proper substrate for acid-loving plants

3. Any stratum or layer lying underneath another.