cancroid vs lichen

cancroid

noun
  • Any disease that resembles cancer 

  • Squamous cell carcinoma 

adj
  • Of or pertaining to cancer, especially to squamous cell carcinoma 

  • Resembling a crab 

lichen

noun
  • Something which gradually spreads across something else, causing damage. 

  • Any of many symbiotic organisms, being associations of algae and fungi, often found as white or yellow-to-blue–green patches on rocks, old walls, etc. 

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