Mohammedan vs raghead

Mohammedan

noun
  • Muslim. 

adj
  • Muslim, Islamic. 

  • relating to Mohammed. 

raghead

noun
  • A Muslim, Arab, Hindu, Sikh, Indian or member of any group that traditionally wears a headdress such as a turban, keffiyeh or headscarf. 

How often have the words Mohammedan and raghead occurred in a corpus of books? (source: Google Ngram Viewer )