暗自 (àn zì) is an adverb meaning 'inwardly,' 'secretly,' or 'to oneself' — describing thoughts, feelings, or actions that occur privately, without outward expression. The character 暗 (àn) means 'dark,' 'hidden,' or 'concealed,' while 自 (zì) means 'self.' Together, they literally suggest 'hidden self' — emphasizing internal, unspoken mental activity. It’s commonly used to describe quiet emotional reactions like worry, joy, or determination that one keeps to oneself.

This word appears frequently in written Chinese and formal spoken contexts, especially in narratives, essays, and dialogues where inner states are revealed. It often modifies verbs like 想 (think), 喜欢 (like), 决定 (decide), or 叹气 (sigh). Unlike colloquial alternatives, 暗自 carries a subtle literary tone and implies conscious restraint — the subject chooses not to reveal their feeling or intention externally, even if others might suspect it.