optimist
n. countablen. someone who always expects good things to happen or looks for the positive side of a situation. You are an optimist if you believe the future will be successful.
n. a person disposed to take a favourable view of events or conditions and to expect the most positive outcome. Often contrasted with 'pessimist'.
As an optimist, she always sees the glass as half full.
Even after the project failed, the team's lead optimist insisted that the experience provided valuable lessons for their next attempt.
While critics argued the plan was unrealistic, the lead architect remained a staunch optimist, convinced that innovative engineering could overcome the site's natural limitations.
From French optimiste, from Latin optimus (“best”) + -ist.
Commonly used in the phrase 'an eternal optimist' to describe someone whose positivity never fades.