shake-up (in/of something) a situation in which a lot of changes are made to a company, an organization, etc. in order to improve the way in which it works a management shake-up Union leaders are calling for a major shake-up of the system.Extra examples Police forces face the biggest shake-up in their 150-year history. The headline read ‘Local council plans shake-up’. The paper calls for an urgent shake-up in the health-care system. The paper calls for an urgent shake-up in the system for looking after the elderly. This case could lead to a shake-up of the prison system. a major shake-up at the company a radical shake-up in the chemical industry the posts that were scrapped in the recent shake-up What the industry needs is a good shake-up.