'未婚' literally means 'not yet married', formed by the character 未 (wèi), meaning 'not yet' or 'have not', and 婚 (hūn), short for 婚姻 (hūnyīn, 'marriage'). It functions as an adjective describing a person’s marital status — specifically someone who has never been legally married. Unlike the more formal term '单身' (dānshēn, 'single'), '未婚' emphasizes the absence of marriage itself, not just current relationship status; it appears frequently in official documents, surveys, and demographic contexts.

The term is neutral in register but leans slightly formal or bureaucratic — you’ll see it on forms, ID applications, or census reports rather than casual conversation. It does not imply anything about dating status, cohabitation, or personal choice; it is strictly legal and factual. While often used with nouns like '人士' (rénshì, 'person') or '者' (zhě, 'one who...'), it can also stand alone as a predicate: '他未婚' (Tā wèihūn, 'He is unmarried').