From Longman Dictionary of Contemporary Englishsunset industryˈsunset ˌindustry noun [countable] an industry that uses old equipment and methods, usually in an area that once had many industries like it, and that is becoming less successful → sunrise industry sunset industries such as steel
Examples from the Corpus
sunset industry• In such circumstances, an industrial policy that seeks faster and more efficient rationalization of the sunset industry may be advantageous.From Longman Business Dictionarysunset industryˈsunset ˌindustry [countable]COMMERCE an industry involved in an old TECHNOLOGY, often in an old industrial area, and often one which is getting smallerThe EU has often been engaged in protecting sunset industries such as the steel industry. → industry 