As a Noun: 1. The process of becoming larger in size. English = expansion. 2. A raised, curved shape on the surface of your body, that appears as a result of an injury or an illness. English = swelling. As a Verb or Adjective: 1. To become big or bigger in all directions. English = expand. 2. To become larger and rounder by being filled with air or liquid, especially a part of your body. English = swell.