1. 下层;底层;深层特征;隐性特质
A substratum of something is a layer that lies under the surface of another layer, or a feature that is less obvious than other features.

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

e.g. the Celtic languages of Britain are a substrate for English

Synonym: substrate

2. any stratum or layer lying underneath another

Synonym: substrate

3. a surface on which an organism grows or is attached

e.g. the gardener talked about the proper substrate for acid-loving plants

Synonym: substrate