mistress vs running dog

mistress

verb
  • To act or take the role of a mistress. 

  • Of a woman: to master; to learn or develop to a high degree of proficiency. 

noun
  • The other woman in an extramarital relationship, generally including sexual relations 

  • A female companion to a master (a man with control, authority or ownership) 

  • A woman, specifically one with great control, authority or ownership 

  • a woman regarded with love and devotion; a sweetheart 

  • A married woman; a wife 

  • A female teacher 

  • A dominatrix 

  • A woman well skilled in anything, or having the mastery over it 

running dog

noun
  • A lackey; a lapdog; an unprincipled person who helps or flatters other, more powerful and often evil people. 

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