'Lion's roar' (shī zi hǒu) is a classical Chinese idiom rooted in Buddhist and literary tradition, where the lion symbolizes courage, authority, and unshakable truth. Literally, 狮 means 'lion', 子 is a grammatical suffix that forms nouns (here turning 'lion' into a noun phrase), and 吼 means 'to roar'. Together, the term evokes the powerful, commanding sound of a lion — not as literal animal behavior, but as a metaphor for bold, fearless, and morally grounded speech or action.

This expression appears frequently in formal or literary contexts: a teacher delivering an inspiring lecture, a leader speaking with conviction against injustice, or a scholar refuting falsehoods with clarity and strength. It carries positive connotations of moral courage and rhetorical power, never mere loudness or aggression. While rare in casual daily speech, it’s widely understood in educated circles and often used in essays, speeches, or media commentary to praise principled assertiveness.