肃清 (sù qīng) is a formal, strong verb meaning 'to thoroughly eliminate' or 'to completely eradicate', especially harmful, undesirable, or corrupt elements. The character 肃 (sù) conveys seriousness, strictness, and solemnity—often associated with discipline or purification—while 清 (qīng) means 'clear', 'clean', or 'pure'. Together, they emphasize a rigorous, systematic removal to restore order, safety, or integrity. This word carries political, social, or institutional weight and is commonly used in official discourse, public health campaigns, anti-corruption efforts, and security contexts.

It implies more than simple removal: it suggests deep-rooted cleansing—like eliminating disease vectors from an ecosystem or purging corrupt practices from an organization. Because of its gravity and formality, 肃清 is rarely used in casual speech or for minor issues. It often appears with objects like '隐患' (hidden dangers), '毒瘤' (malignant tumors), '腐败分子' (corrupt elements), or '病原体' (pathogens), underscoring its association with systemic threats requiring decisive action.