approximal vs touching

approximal

adj
  • Contiguous 

  • Near or adjacent 

touching

noun
  • The act by which something is touched. 

  • A snack served with alcoholic drinks in an informal environment. 

prep
  • Regarding; concerning. 

adj
  • Provoking sadness and pity; that can cause sadness or heartbreak among witnesses to a sad event or situation. 

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