autoeroticism vs fingering

autoeroticism

noun
  • The practise of stimulating oneself sexually, masturbation 

fingering

noun
  • The act of using the fingers to penetrate and sexually stimulate one's own or another person's vagina or anus. 

  • The act of using one's fingers in the playing of a musical instrument. 

  • A thick woollen yarn for stockings. 

  • A specific method of using the fingers to play an instrument. 

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