lousy vs unheard-of

lousy

adj
  • Infested with lice. 

  • Unwell; under the weather. 

  • Dirty or untidy. 

  • Remarkably bad; of poor quality. 

  • Underhanded; mean; contemptible. 

  • Filled or packed (with something, usually bad). 

unheard-of

adj
  • Unknown or known to only few people. 

  • Previously unknown; unprecedented. 

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