over-optimistic
adjective /ˌəʊvər ˌɒptɪˈmɪstɪk/
/ˌəʊvər ˌɑːptɪˈmɪstɪk/
- too confident that something will be successful
- I'm not over-optimistic about my chances of getting the job.
- showing more confidence that something will be successful than is shown to be right or reasonable by later events
- The sales forecasts turned out to be over-optimistic.