[] 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（机构的）重大调整，重组◆a management shake-up管理层大改组◆Union leaders are calling for a major shake-up of the system.工会领导人呼吁对现行制度进行大刀阔斧的改革。◆a shake-up in the mobile phone industry移动电话行业的大变革