As a Noun: 1. The part of something that normally faces towards the ground. English = underside. As a Verb or Adjective: 1. To be located directly below or beneath something. English = (be) under. 2. To move so that you are located directly below or beneath something. English = go under. 3. To be located under the surface of the ground. English = (be) underground. 4. To be in the power or control of a particular person or government. English = (be) under.