hygienic vs pestiferous

hygienic

adj
  • Whose expansion is guaranteed not to cause the accidental capture of identifiers. 

  • Pertaining to hygiene; clean, sanitary. 

pestiferous

adj
  • containing organisms that cause contagious diseases 

  • annoying, vexatious 

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