A literary or formal term for the feeling of compassion or pity, often used in philosophical or classical contexts. Rare in everyday conversation.
Compassion is one of the Four Beginnings taught by Mencius.
彼の話を聞いて、自然と惻隠の情が湧いた。
Hearing his story, a feeling of pity naturally welled up.
From Chinese 惻隱之心 (cèyǐn zhī xīn), a concept in Mencius referring to the innate feeling of compassion. The Japanese reading is on'yomi.