procreant vs unproductive

procreant

adj
  • Of or pertaining to procreation; procreative. 

  • That procreates. 

noun
  • One who, or that which, procreates. 

unproductive

adj
  • No longer used to produce new words (see examples). 

  • Not productive; useless; fruitless. 

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