cognate vs undifferentiated

cognate

adj
  • Of the same or a similar nature; of the same family; proceeding from the same stock or root. 

  • Allied by blood; kindred by birth; specifically (law) related on the mother's side. 

  • Descended from the same source lexemes (same etymons) of an ancestor language. 

noun
  • One of a number of things allied in origin or nature. 

  • A word either descended from the same base word of the same ancestor language as the given word, or strongly believed to be a regular reflex of the same reconstructed root of proto-language as the given word. 

undifferentiated

adj
  • Not differentiated, not different, alike 

  • describes a plant body where the vascular tissue has not developed, as in the thallophytes 

  • describes tissues where the individual cells have not yet developed mature or distinguishing features, or describes embryonic organisms where the organs cannot be identified. 

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