마음이 쓰리다.

The idiom '마음이 쓰리다' (ma-eum-i sseu-ri-da) is a combination of two words: '마음' (ma-eum), meaning 'heart' or 'mind,' and '쓰리다' (sseu-ri-da), an adjective meaning 'to be sore,' 'to be stinging,' or 'to be painful.' The origin of '쓰리다' can be traced back to Middle Korean, where it appeared as '리다' (pssu-ri-da). This verb originally referred to a physical sensation of stinging or soreness, often associated with wounds or irritation. Over time, its usage expanded metaphorically to describe emotional pain. The combination with '마음' (heart/mind) emphasizes that the pain is deeply emotional and internal, rather than physical. Therefore, '마음이 쓰리다' literally translates to 'one's heart stings' or 'one's mind is sore,' vividly conveying the feeling of deep emotional pain, sorrow, or regret that is compared to a physical stinging sensation.