ebullient vs pessimistic

ebullient

adj
  • Enthusiastic; high-spirited. 

  • Boiling or agitated as if boiling. 

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 ebullient and pessimistic occurred in a corpus of books? (source: Google Ngram Viewer )