改革 (gǎi gé) means 'reform' — a fundamental, often systematic change intended to improve institutions, policies, or practices. The character 改 (gǎi) means 'to change' or 'to alter', while 革 (gé) originally meant 'to remove the hide from an animal' but evolved to signify 'to strip away the old' or 'to revolutionize'. Together, they convey purposeful, structural transformation — not minor adjustments, but deliberate, large-scale renewal.

This word is most commonly used in formal, institutional, or historical contexts: economic reform, educational reform, political reform, or enterprise management reform. It frequently appears in official discourse, news reports, and academic writing. While it can function as a verb (e.g., 改革教育), it’s more often used as a noun (e.g., 教育改革). Unlike casual words like 修改 (xiūgǎi, 'to revise'), 改革 implies deep, consequential change with broad social impact.