disarticulate vs unhitch

disarticulate

verb
  • To disjoint. 

  • To amputate (a limb) at a joint without cutting the bone. 

unhitch

verb
  • To disconnect; to detach; to undo that which is hitched. 

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