Substrate (semiconductor) definition

(1) An indigenous language that contributes features to the language of an invading people who impose their language on the indigenous population

"The Celtic languages of Britain are a substrate for English"

(2) Any stratum or layer lying underneath another

(3) A surface on which an organism grows or is attached

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

(4) The substance that is acted upon by an enzyme or ferment