notable vs unknown

notable

noun
  • A person or thing of distinction. 

adj
  • Worthy of note; remarkable; memorable; noted or distinguished. 

  • Easily noted (without connotations of value); clearly noticeable, conspicuous. 

  • That can be observed; perceptible. 

unknown

noun
  • A person of no identity; a nonentity 

  • A variable (usually x, y or z) whose value is to be found. 

  • Any thing, place, or situation about which nothing is known; an unknown fact or piece of information. 

adj
  • Not known; unidentified; not well known. 

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