encouragement vs shot in the arm

encouragement

noun
  • The feeling of being encouraged 

  • Words or actions that increase someone's confidence 

  • Something that incites, supports, promotes, protects or advances; incentive 

  • The act of encouraging 

shot in the arm

noun
  • A stimulus; a boost in energy, morale, or well-being. 

  • An injection of a drug into the arm, whether for medical or recreational purposes. 

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