As a Noun: 1. A structure which has a roof and walls, for example a house or a factory. English = building. 2. A person whose job is to build houses and other buildings. English = builder. As a Verb or Adjective: 1. To make a structure which has a roof and walls, such as a house or a factory. English = build, construct, erect. 2. To grow and change over a period of time into a better or more complete thing. English = develop. Idiomatic English = build up.