at ease vs taken aback

at ease

prep
  • Allowed to refrain from being in rigid formation. 

  • Free of anxiety; not stressed or tense. 

  • In a relaxed position with the feet apart rather than at attention. 

taken aback

adj
  • Said of a ship, when the wind, suddenly changing, forces the sails aft against the mast. 

  • Surprised, shocked. 

How often have the words at ease and taken aback occurred in a corpus of books? (source: Google Ngram Viewer )