moiety vs subfamily

moiety

noun
  • A share or portion, especially a smaller share. 

  • Each descent group in a culture which is divided exactly into two descent groups. 

  • A specific segment of a molecule. 

  • A half. 

subfamily

noun
  • A secondary or subordinate grouping. 

  • A taxonomic category ranking between a family and a genus; formerly called a tribe 

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