family name vs to-name

family name

noun
  • A given name common in a family, or already borne by someone in the family (in the context of naming someone in the family after that family member). 

  • A surname. 

to-name

noun
  • A name in addition to the Christian name and surname of an individual, to distinguish him or her from others of the same name and usually indicating descent, place of residence, or some personal quality or attribute. Such to-names are often employed where the same families continually intermarry, and where consequently the same name is common to many individuals. 

  • A name added to another name; surname. 

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