失约 (shī yuē) literally means 'to lose an appointment' — the character 失 (shī) means 'to lose' or 'to fail', and 约 (yuē) means 'appointment', 'arrangement', or 'agreement'. Together, they form a verb meaning 'to break an appointment' or 'to fail to keep a promise to meet someone'. It implies a breach of social trust, often carrying mild disapproval or regret.

This word is commonly used in everyday spoken and written Chinese when referring to missed meetings, canceled plans, or unfulfilled commitments — especially those made informally between friends, colleagues, or family. It’s more formal and weighty than simply saying 'I didn’t go'; it emphasizes the relational consequence of not showing up as promised. While not inherently harsh, repeated 失约 can damage credibility or friendship. It’s typically used with subjects like 我, 他, or 她, and often appears with time phrases (e.g., 昨天, 上周) or explanations (e.g., 因为生病, 临时有事).