disburden vs unmoor

disburden

verb
  • To rid of a burden; to free from a load carried; to unload. 

  • To free from a source of mental trouble. 

unmoor

verb
  • To set free or loose. 

  • To weigh anchor. 

  • To unfix or unsecure (a moored boat). 

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