mu vs unbeing

mu

noun
  • Nothingness; nonexistence; the illusory nature of reality. 

  • The 12th letter of the Modern Greek alphabet. 

  • A unit of surface area, currently equivalent two-thirds of a decare (about 666 meters squared). 

intj
  • Neither yes nor no. 

unbeing

noun
  • Nonexistence. 

  • A nonbeing; an entity of no existence or significance. 

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