mantra vs middle name

mantra

noun
  • A phrase repeated to assist concentration during meditation. 

  • The hymn portions of the Vedas; any passage of these used as a prayer. 

  • A slogan or phrase often repeated. 

middle name

noun
  • A trait, activity, or action closely associated with or aptly describing a person. 

  • A name between the first given name and the family name or surname; a second or subsequent given name. 

  • One's mother's maiden name. 

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