subdivision vs subfamily

subdivision

noun
  • A division into smaller pieces of something that has already been divided. 

  • Such a piece that has been divided. 

  • A parcel of land that has been divided into lots. 

  • A group of houses created by the same builder or in the same general area. 

  • A gated community. 

verb
  • To separate something into smaller pieces. 

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 subdivision and subfamily occurred in a corpus of books? (source: Google Ngram Viewer )