breather vs commencement

breather

noun
  • A short break; a rest or respite. 

  • A spatially localized, time-periodic excitation in a one-dimensional lattice. 

  • An air inlet path to the crankcase 

  • Something or someone that breathes. 

  • A heavy breather. 

commencement

noun
  • The first existence of anything; act or fact of commencing; the beginning. 

  • The day when degrees are conferred by colleges and universities upon students and others. 

  • A graduation ceremony, from a school, college or university. 

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