Imperialism is a policy of extending rule over other countries. An age of imperialism.
It covers direct rule and the softer kind done through money and trade. Imperialism is almost always a word used against somebody rather than about oneself.
1nounimperialismA policy of extending rule over other countries.
“The whole century is taught as a history of imperialism.”
imperialism is a policy.
From imperial + -ism.
Etymology from Wiktionary, CC BY-SA