initials vs patronymic

initials

noun
  • An abbreviation of a person's name, constructed by taking the initial letters of first, last, and sometimes middle name(s). See monogram 

patronymic

noun
  • A name acquired from one's father's, grandfather's or earlier (male) ancestor's first name. Some cultures use a patronymic where other cultures use a surname or family name; other cultures (like Russia) use both a patronymic and a surname. 

  • A name acquired from one's father. 

adj
  • Derived from one's ancestors. 

  • Derived from one's father. 

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