caught on the hop vs surprised

caught on the hop

adj
  • In a situation of change, especially from a known to an unknown state. 

  • In a situation for which one is unprepared. 

surprised

adj
  • Caused to feel surprise, amazement or wonder, or showing an emotion due to an unexpected event. 

How often have the words caught on the hop and surprised occurred in a corpus of books? (source: Google Ngram Viewer )