at ease vs pessimistic

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. 

pessimistic

adj
  • Marked by pessimism and little hopefulness; expecting the worst. 

  • Pertaining to the worst-case scenario. 

  • Taking out exclusive locks on data to prevent conflicts with other processes that might modify it. 

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