unlikely vs unthought of

unlikely

noun
  • Something or somebody considered unlikely. 

adv
  • In an improbable manner. 

adj
  • Not holding out a prospect of success; likely to fail; unpromising. 

  • Not likely; improbable; not to be reasonably expected. 

unthought of

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