鼻涕 (bí tì) literally combines 鼻 (bí), meaning 'nose', and 涕 (tì), an older literary word for 'tears' or 'mucus'. In modern Chinese, it specifically refers to nasal mucus — what English speakers call 'snot'. It’s a neutral, colloquial noun used in everyday speech, especially when describing colds, allergies, or seasonal congestion. While not vulgar, it’s informal and rarely appears in formal medical contexts (where terms like 鼻分泌物 ní fēnmìwù — 'nasal secretion' — are preferred).

The word is often used with verbs like 流 (liú, 'to flow'), 擦 (cā, 'to wipe'), or 打喷嚏 (dǎ pēntì, 'to sneeze'). It frequently appears in descriptions of illness or childhood behavior — for example, children with runny noses or adults recovering from the flu. Unlike English 'snot', which can be jarring or childish in some registers, 鼻涕 carries no strong stigma but is best avoided in polite or clinical writing.