ending vs onset

ending

noun
  • A termination or conclusion. 

  • The last part of something. 

  • The last morpheme of a word, added to some base to make an inflected form (such as -s in "dogs"). 

onset

noun
  • The initial portion of a syllable, preceding the syllable nucleus. 

  • The beginning of a musical note or other sound, in which the amplitude rises from zero to an initial peak. 

  • The initial phase of a disease or condition, in which symptoms first become apparent. 

  • A setting about; a beginning. 

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