The definition of colonialism is the act of one nation controlling another for economic gain.
An example of colonialism was England’s control over India.
the system or policy by which a country maintains foreign colonies, esp. in order to exploit them economically
The policy or practice of a wealthy or powerful nation's maintaining or extending its control over other countries, especially in establishing settlements or exploiting resources.
(countable and uncountable, plural colonialisms)
colonial + -ism