boundless vs ephemeral

boundless

adj
  • Without bounds, unbounded. 

ephemeral

noun
  • Something which lasts for a short period of time. 

adj
  • Usually dry, but filling with water for brief periods during and after precipitation. 

  • Lasting for a short period of time. 

  • Existing for only one day, as with some flowers, insects, and diseases. 

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