'Zǒu kāi' literally combines 'zǒu' (to walk/go) and 'kāi' (open/away), but together they form an inseparable verb meaning 'to go away' or 'to leave' — often with a sense of dismissal, urgency, or impatience. It functions as a command or request to depart from a place or situation, and is commonly used in spoken Mandarin rather than formal writing.

The phrase is typically directed at people (or sometimes animals) and implies physical movement out of the current location or proximity. While neutral in structure, tone and context heavily influence its politeness: said gently to a child, it may sound caring; said sharply to an adult, it can sound rude or confrontational. It does not take objects directly — you don’t 'zǒu kāi something' — and usually appears sentence-finally or after the subject ('Nǐ zǒu kāi!').