optimistic vs suspicious

optimistic

adj
  • Expecting the best in all possible ways. 

  • Allowing other processes to perform transactions on the same data at the same time, and checking for conflicts only when changes need to be written back. 

suspicious

adj
  • Arousing suspicion. 

  • Distrustful or tending to suspect. 

  • Expressing suspicion 

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