樂觀主義者;樂觀者
Optimist \Op"ti*mist\, n. [Cf. F. optimiste.] 1. (Metaph.) One who holds the opinion that all events are ordered for the best. 2. One who looks on the bright side of things, or takes hopeful views; -- opposed to {pessimist}.
optimist n : a person disposed to take a favorable view of things [ant: {pessimist}]