'丢脸' (diū liǎn) literally means 'to lose face' — a vivid idiom rooted in traditional Chinese social values where 'face' (liǎn) symbolizes one’s dignity, reputation, or social standing. The verb 丢 (diū) means 'to lose' or 'to discard', so together the phrase conveys the emotional and social discomfort of embarrassing oneself or damaging one’s image in front of others.

This expression is commonly used in informal spoken and written Chinese to describe situations involving public mishaps, social blunders, or failures that cause shame or humiliation — such as tripping in front of colleagues, forgetting a speech, or being caught lying. It carries a strong emotional weight and is often softened with modifiers like 真 (zhēn, 'really') or 太 (tài, 'too') for emphasis. While not inherently offensive, it’s rarely used in formal contexts or when addressing superiors directly.