fettering vs impediment

fettering

noun
  • The act by which something is fettered or constricted. 

impediment

noun
  • A hindrance; that which impedes or obstructs progress. 

  • Baggage, especially that of an army; impedimenta. 

  • A disability, especially one affecting the hearing or speech. 

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