collaboration vs encumbrance

collaboration

noun
  • Treasonous cooperation. 

  • The act of collaborating. 

  • A production or creation made by collaborating. 

encumbrance

verb
  • To apply an encumbrance to (property, etc.). 

noun
  • An interest, right, burden, or liability attached to a title of land, such as a lien or mortgage. 

  • Something that encumbers; a burden that must be carried. 

  • One who is dependent on another. 

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