attorn vs obligate

attorn

verb
  • To transfer one's obligations from a person to another person. 

  • To consent to the transfer of one's obligations as tenant under a lease to a new landlord. 

  • To acknowledge the jurisdiction of (a particular court) over one's dispute. 

obligate

verb
  • To commit (money, for example) in order to fulfill an obligation. 

  • To bind, compel, constrain, or oblige by a social, legal, or moral tie. 

  • To cause to be grateful or indebted; to oblige. 

adj
  • Requiring a (specified) way of life, habitat, etc.. 

  • Indispensable; essential; necessary; obligatory; mandatory; unavoidably invoked. 

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