It kinda reminds me of the polish word "Murzyn". It's pretty archaic, ethymologically come from latin "maurus" either though german "Mohr" (for people of Maghreb) or from polish "murzyć" ("to blacken something"), due to not much historical contacts it really means something roughly similar to "negro" and just as that word it was and still used in very different contexts. And due to that, it was deemed not racist enough for racists and so an entirely mirror to n-word was coined ("czarnuch", this one have only one context).

Today, it is officially (by Polish Language Council for example) unadvised to use the word "Murzyn", since it became more and more pejorative in recent 3 decades, though it's still a bit ambigous since even some black people living in Poland defended it.

Conclusion, such words can be loaded even in one's native language, and he should know better to throw in foreign slang he might heard on the street.