difficulty vs worry

difficulty

noun
  • The state of being difficult, or hard to do. 

  • Physical danger from the environment, especially with risk of drowning 

  • An obstacle that hinders achievement of a goal. 

  • An objection. 

  • An awkward situation or quarrel. 

  • That which cannot be easily understood or believed. 

worry

noun
  • An instance or cause of such a feeling. 

  • A strong feeling of anxiety. 

  • A person who causes worry. 

verb
  • To harass; to irritate or distress. 

  • To touch repeatedly, to fiddle with. 

  • To be troubled; to give way to mental anxiety or doubt. 

  • To seize or shake by the throat, especially of a dog or wolf. 

  • Disturb the peace of mind of; afflict with mental agitation or distress. 

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