perpetuity vs unboundedness

perpetuity

noun
  • The quality or state of being perpetual; endless duration; uninterrupted existence. 

  • An annuity in which the periodic payments begin on a fixed date and continue indefinitely. 

  • Something that is perpetual. 

  • A limitation intended to be unalterable and of indefinite duration; a disposition of property which attempts to make it inalienable beyond certain limits fixed or conceived as being fixed by the general law. 

unboundedness

noun
  • The condition of being unbounded 

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