noun
A broad word for a person's inner life: thoughts, emotions, intentions, conscience, or mental/spiritual strength. English often chooses either 'mind' or 'heart' depending on context.
彼女の言葉に心を打たれた。
I was deeply moved by her words.
試験の前で心が落ち着かない。
My mind won't settle down before the exam.
noun
Limited, old-fashioned or literary use for the intended meaning or point of a phrase, poem, riddle, or similar expression. In ordinary modern speech, 意味 is more common.
古い言い方で、「このなぞなぞの心」といえば「このなぞなぞの意味」を指す。
In an old-fashioned expression, このなぞなぞの心 means the meaning of this riddle.