In Libya and especially in the South where we have a big percentage that are black, people call black people "3abed" in Arabic which literally translates into slave. Slavery was around in Libya only 100 years ago, so thats probably the reason people still use that word. The word kinda lost its meaning when said in Libyan slang and is rarely used to racially insult black people, its so common in Southern Libya that even black people don't really take much offense from the word anymore.
Does that make the word ok? Absolutely not, its a terrible phenomenon and it should be eradicated from the language, whether it is intended to insult or degrade black people or not is absolutely irrelevant. The world should never be used.
Whatever Suarez says, and whether or not the word is accepted in South America is irrelevant. He should be punished.