An insult used against blacks living in a non-African
country.
What people forget when they use it, however, is that in order to "go back" to somewhere, you have to have been born in that place. Most likely, the black who you tried to insult was born in a Western country, and no Western country is located in the continent of Africa.
If you want to use this insult: you should go back to
school and learn some geography. While you're there, learn some scientific facts, such as how all humans can
trace their origins back to Africa, not just blacks. It has been proven: the most
racist communities also happen to be the least educated.