启程 literally combines 启 (qǐ), meaning 'to begin' or 'to initiate', and 程 (chéng), meaning 'journey' or 'course'. Together, they form a formal, literary verb meaning 'to set out' or 'to depart' — especially on a planned trip or journey. It emphasizes the moment of departure, often with intention and preparation, and is commonly used in contexts like travel, migration, or official missions.

The word carries a tone of purpose and significance — you wouldn’t use it for casually walking to the store. It frequently appears in written Chinese (news reports, announcements, literature) and formal speech, often paired with time phrases (e.g., 明早启程, 'depart tomorrow morning') or destinations (e.g., 启程赴日本, 'set out for Japan'). While grammatically a verb, it does not take aspect markers like 了 or 过 as readily as colloquial verbs do — instead, it’s typically used in its base form or with modal verbs like 将 or 要.