As a Noun: 1. The action of something moving slowly downwards through air or water. 2. The action of moving slowly downwards, especially below the surface of water. English = sinking. As a Verb or Adjective: 1. To move slowly downwards through air or water. 2. To move slowly downwards, especially below the surface of water. English = sink. 3. To move slowly downwards through the air. English = float down.