ilk vs subfamily

ilk

noun
  • A type, race or category; a group of entities that have common characteristics such that they may be grouped together. 

adj
  • Very; same. 

subfamily

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

  • A secondary or subordinate grouping. 

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