immature vs subalternate

immature

adj
  • Childish in behavior; juvenile. 

  • Not fully formed or developed; not grown. 

noun
  • An immature member of a species. 

subalternate

adj
  • Subaltern; inferior; subordinate. 

  • Succeeding by turns; successive. 

noun
  • A particular proposition, as opposed to a universal one. 

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