down in the mouth 痛心（成语）

英文释义

(IDIOM) Sad; discouraged; lost in hopeless despair. (NOTE: sometimes hyphenated as "down-in-the-mouth").

例句

My son's favorite basketball team lost their championship game last night, so he has been feeling down in the mouth all day.

我儿子最爱的篮球队昨晚输掉了总决赛，他为此痛心了一整天。