interest group
From Longman Dictionary of Contemporary EnglishRelated topics: Groupingsinterest groupˈinterest ˌgroup noun [countable] PPGa group of people who join together to try to influence the government in order to protect their own particular rights, advantages etc SYN lobbyExamples from the Corpusinterest group• The system of interest group pressure ensuring state responsiveness to its publics thus appears to be flawed.