IPA: /ˌæntiˈkoʊləˌnɪzəm/
KK: /ˌæntiˈkoʊləˌnɪzəm/
A movement or ideology that fights against the control and domination of one country over another, particularly in the context of historical colonial rule.
The rise of anticolonialism in the 20th century led to many countries gaining independence from colonial powers.
Anticolonialism is formed from "anti-" (meaning against) and "colonialism" (from "colonial" derived from Latin "colonia" meaning settlement, and "-ism" indicating a doctrine or belief). The term refers to the belief or movement against colonial rule and the establishment of settlements by foreign powers.
Think of being 'against' ('anti-') the idea of 'settlements' ('colonialism') imposed by foreign powers — that's what anticolonialism means.