Blue Moon in Chinese: Translation and Meaning

"Blue moon" in Chinese is 蓝月亮 (lán yuè liàng):

• 蓝 (lán) = blue
• 月亮 (yuè liàng) = moon

This is the literal translation; the idiomatic "once in a blue moon" is 千载难逢 (qiān zǎi nán féng) or 难得一见 (nán dé yī jiàn).