immensurable vs unplumbed

immensurable

adj
  • unmeasurable, immeasurable; not able to be measured, therefore connoting extremely large 

unplumbed

adj
  • Not measured for depth, with or as if with a plumb. 

  • Not assayed or measured in any way. 

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