/ ɪmˈpɪəriəlɪzəm; NAmE -ˈpɪr-/ noun [ U ] (usually disapproving )
1.
a system in which one country controls other countries, often after defeating them in a war :
Roman imperialism
2.
the fact of a powerful country increasing its influence over other countries through business, culture, etc. :
cultural / economic imperialism
► im·peri·al·is·t (also im·peri·al·is·tic / ɪmˌpɪəriəˈlɪstɪk; NAmE -ˌpɪr-/) adjective :
an imperialist power
imperialist ambitions