ascetic vs dervish

ascetic

adj
  • Characterized by rigorous self-denial or self-discipline; austere; abstinent; involving a withholding of physical pleasure. 

  • Of or relating to ascetics 

noun
  • One who is devoted to the practice of self-denial, either through seclusion or stringent abstinence. 

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. 

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