cleanliness vs onus

cleanliness

noun

  • Ritual purity. 

  • The property of being cleanly, or habitually clean; good hygiene. 

onus

noun

  • A legal obligation. 

  • Burden of proof, onus probandi. 

  • Stigma. 

  • Blame. 

  • Responsibility; burden. 

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