optimism
n. 乐观；乐观主义
例句
His new-found optimism dissolved.
他刚刚建立的乐观情绪消失了。
《柯林斯英汉双解大词典》
He radiated self-confidence and optimism.
他显得自信乐观。
《牛津词典》
There are very real grounds for optimism.
的确有理由可以乐观。
