non-gradable vs rare

non-gradable

noun
  • Any adjective that is not gradable. 

adj
  • That cannot be graded. 

  • (of an adjective) Describing a quality that cannot normally be varied because it is extreme (e.g. freezing), absolute (e.g. dead), or classification (e.g. nuclear). 

rare

noun
  • A scarce or uncommon item. 

verb
  • To rear, bring up, raise. 

  • To rear, rise up, start backwards. 

adj
  • Thin; of low density. 

  • Very uncommon; scarce. 

  • Particularly of meat, especially beefsteak: cooked very lightly, so the meat is still red. 

  • Good; enjoyable. 

How often have the words non-gradable and rare occurred in a corpus of books? (source: Google Ngram Viewer )