'勿食' is a formal, written imperative phrase meaning 'do not eat'. It combines the classical negative adverb 勿 (wù), which means 'do not' or 'must not', and the verb 食 (shí), meaning 'to eat'. Unlike the more common spoken prohibition '不要吃' (bú yào chī), '勿食' appears primarily on warning labels, safety instructions, or official notices—especially where food safety or toxicity is involved. Its tone is authoritative and urgent, often implying serious risk.

This phrase is typically used in contexts like medicine packaging, chemical containers, or wild mushroom guides, where consumption could cause harm. It’s rarely used in casual speech or daily conversation; native speakers would say '别吃' or '不能吃' instead. The characters are monosyllabic and carry classical literary weight, making '勿食' concise but highly serious—similar in function to English warnings like 'DO NOT CONSUME' or 'POISON: DO NOT EAT'.