The Collaborative International Dictionary
Anti-imperialism \An`ti-im*pe"ri*al*ism\, n. Opposition to imperialism.
Note: This term was applied originally in the United States, after the Spanish-American war (1898), to the attitude or principles of those opposing territorial expansion; in England, of those, often called Little Englanders, opposing the extension of the empire and the closer relation of its parts, esp. in matters of commerce and imperial defense. After the second world war, the term became used for opposition to any hegemony of one power over a foreign territory, and to the support for the national independence of territories, as in Africa, which were controlled by European nations. -- An`ti-im*pe"ri*al*ist, n. -- An`ti-im*pe`ri*al*is"tic, a. [Webster 1913 Suppl. +PJC] ||
Wiktionary
n. Any belief or practice which opposes imperialism.
Wikipedia
"Anti-imperialism" in political science and international relations is a term used in a variety of contexts, usually by nationalist movements, who want to secede from a larger polity (usually in the form of an empire, but also in a multi-ethnic sovereign state) or as a specific theory opposed to capitalism in Marxist–Leninist discourse, derived from Vladimir Lenin's work Imperialism, the Highest Stage of Capitalism. A less common usage is by isolationists who oppose an interventionist foreign policy.
People who categorise themselves as anti-imperialists, often state that they are opposed to colonialism, colonial empire, hegemony, imperialism, and territorial expansion of a country beyond its established borders. The phrase gained a wide currency after the Second World War and at the onset of the Cold War as political movements in colonies of European powers promoted national sovereignty. Some "anti-imperialist" groups who opposed the United States supported the power of the Soviet Union, such as in Guevarism, while in Maoism, this was criticized as " social imperialism". In the Arab and Muslim world, the term is often used in the context of Anti-Zionist nationalist and religious movements.
Usage examples of "anti-imperialism".
Here he was, on the verge of losing everything he'd worked for, about to be used as a weapon that would cudgel the civil rights movement and anti-fascism and anti-imperialism and labor and everything else that mattered to him, knowing that his name would be anathema, that anyone he'd ever associated with would soon be facing the same treatment.