未曾 is an adverb meaning 'never (before)' — it expresses that something has not occurred at any time up to the present moment. It combines two characters: 未 (wèi), meaning 'not yet' or 'not', and 曾 (céng), meaning 'already' or 'ever'. Together, they form a classical and formal negation of prior experience — literally 'not yet ever'. Unlike the more colloquial 没有 (méiyǒu) + verb, 未曾 is literary, often found in written Chinese, formal speech, historical narratives, or introspective expressions.

This word typically precedes verbs (e.g., 未曾见过, 未曾听说) and conveys a sense of personal absence of experience, sometimes with nuance of regret, wonder, or emphasis on novelty. It’s rarely used in casual daily conversation but appears frequently in essays, novels, speeches, and set phrases like 未曾谋面 ('never met in person'). Its tone is slightly elevated and reflective, making it unsuitable for imperative or informal commands.