From Longman Dictionary of Contemporary Englishpressure groupˈpressure group noun [countable] SSOa group or organization that tries to influence the opinions of ordinary people and persuade the government to do something → interest group environmental pressure groups
Examples from the Corpus
pressure group• At present victims must take their claims to court ... a pressure group says the Government should pay.• The society boasts that it has become the most successful single-issue pressure group since William Wilberforce and opposition to the slave trade.• On the other is the pressure group, Birmingham for People, championed by local architect Joe Holyoak. 