From Longman Dictionary of Contemporary Englishgreenfield sitegreen‧field site /ˈɡriːnfiːld ˌsaɪt/ noun [countable] TBCa piece of land that has never been built on before → brownfield siteFrom Longman Business Dictionarygreenfield siteˈgreenfield ˌsitePROPERTY a site used for building where there has never been building or industrial activity in the pastAs the space requirements of companies changed, they sought more open greenfield sites away from the cities. → site