Kafir means one who disbelives,the word KUFR means STATE OF DISBELIEF,now what is so derogatory about this? If you are not a Muslim,then it means you dont belive in Islam,so what is so offensive about this word in arabic? The uncle of Muhammed whose name is Abutalib was very endearing to him and in fact he is the one who took care of Muhammed against his presecutors.But Abutalib died as a KAFIR ie a disbeliver, despite his deepest affection and love for Muhammed. So a KAFIR from islamic perspective is some one who doesnt belive in Islam.Thats all
