dervish vs marabout

dervish

noun
  • Any irregular guerrilla fighter resembling the Sudanese Mahdi in equipment, uniform, tactics, etc. 

  • A citizen or inhabitant of Darawiish (circa 1895–1920 C.E.), an anti-colonial polity in modern Somalia headed by Sufis. 

  • One of the followers of Muhammad Ahmad, the Mahdi of the Sudan, in the 1880s. 

marabout

noun
  • A Muslim holy man or mystic, especially in parts of North Africa. 

  • The tomb or shrine of such a person. 

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