Meaning of “optimistic” - Learner’s Dictionary

optimistic

adjective uk us /ˌɒptɪˈmɪstɪk/

B2 always believing that good things will happen:

We're optimistic about our chances of success.
[ + (that) ] I'm not optimistic that we'll reach an agreement.
→ Opposite pessimistic

(Definition of “optimistic” from the Cambridge Learner’s Dictionary © Cambridge University Press)