乐天主义 lètiānzhǔyì optimism Definitions Defs Origin Strokes Stroke Words Sentences Sents 乐天 樂天 lètiān optimistic carefree and happy-go-lucky; content with one's lot and accepting of the natural course of events主义 主義 zhǔyì noun -ism; doctrine a systematic theory, school of thought, or social or political system