1. (

• substrate

) the substance that is acted upon by an enzyme or ferment ;

2. (

• substrate ,
• substratum ,

) a surface on which an organism grows or is attached; "the gardener talked about the proper substrate for acid-loving plants" ;

3. (

• substrate ,
• substratum

) any stratum or layer lying underneath another ;

4. (

• substrate ,
• substratum

) 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" ;