1853, "ways or speech of colonial persons," from colonial + -ism. Meaning "the system of colonial rule" is from 1886.
The control of one nation by “transplanted” people of another nation — often a geographically distant nation that has a different culture and dominant racial or ethnic group. (See ethnicity.)
Note: A classic example of colonialism is the control of India by Britain from the eighteenth century to 1947.
Note: Control that is economic and cultural, rather than political, is often called neocolonialism.