如约 literally means 'as (rú) the agreement (yuē)' — it functions as an adverb meaning 'as agreed' or 'according to the prior arrangement.' The character 如 means 'as,' 'like,' or 'in accordance with,' while 约 means 'agreement,' 'appointment,' or 'promise.' Together, they form a concise, formal expression used to confirm that someone has fulfilled a commitment regarding time, place, or action.

This phrase is commonly used in both spoken and written Chinese, especially in professional, academic, or polite social contexts. It often appears after verbs like 到达 (arrive), 出席 (attend), 或 履行 (fulfill). While neutral in register, 如约 carries a tone of reliability and respect for commitments — it’s more formal than colloquial alternatives like ‘按时’ (on time) but less stiff than bureaucratic phrases like ‘依约’ (per agreement). It’s frequently paired with verbs indicating punctuality or adherence to plans.