nothingburger vs unknown

nothingburger

noun
  • A person who is a nonentity. 

  • Something of less importance than its treatment suggests. 

  • A person or object that is bland or unremarkable in appearance or impact. 

adj
  • bland or unremarkable in appearance 

  • disreputable, as of a person 

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 nothingburger and unknown occurred in a corpus of books? (source: Google Ngram Viewer )