apocope vs impropriety

apocope

noun
  • The loss or omission of a sound or syllable from the end of a word. 

  • The loss or omission of the last vowel in a word, together with any consonants that follow it. 

impropriety

noun
  • Improper language. 

  • The condition of being improper. 

  • An improper act. 

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