A movement spearheaded by African-American scholars to prove that, despite what most people would like to believe, ancient Africa had her own civilizations, languages, cultures, and history long before the arrival of the first Europeans to the continent.
Afrocentrism is not Black Supremacism. There are Black Supremacists who hold Afrocentric views, but they also hold views that claim to elevate blacks above whites. That is not the aim of Afrocentrism.
A pejorative that white supremacists and other anti-black racist punks throw at anyone who reminds them that "Jungle Jitters" is not an accurate generalization of pre-colonial Africa. Often associated with the obsolete and erroneous belief that any ancient structure in Africa bigger than a grass hovel must have been built by incoming "Mediterranean Caucasoids" since the native "Negroids" are so incapable (as if the average anti-black racist were any better).
If you credit the indigenous dark-skinned peoples of Africa with civilizations like ancient Egypt, Nubia, Ethiopia, Mali, Great Zimbabwe, and so on, you're a black supremacist proponent of Afrocentrism.