system.

1.[c]（思想或理论）体系；方法；制度；体制an organized set of ideas or theories or a particular way of doing sth

2.[c]系统a group of things, pieces of equipment, etc. that are connected or work together

3.[c]身体；（器官）系统a human or an animal body, or a part of it, when it is being thought of as the organs and processes that make it function

4.[sing](informal)（尤指不公正的统治或管理）制度，体系，集团the rules or people that control a country or an organization, especially when they seem to be unfair because you cannot change them