corvid vs onyx

corvid

noun
  • A member of the bird family Corvidae, including crows, ravens, jays, choughs, treepies etc. 

adj
  • Pertaining to or resembling the Corvidae. 

onyx

noun
  • Any of various lycaenid butterflies of the genus Horaga. 

  • A jet-black color, named after the gemstone. 

  • A banded variety of chalcedony, a cryptocrystalline form of quartz. 

adj
  • jet-black 

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