‘一串’ (yī chuàn) is a measure word phrase meaning 'a string of' or 'a set of' items that are physically or conceptually linked—often things strung together, like beads, keys, or sausages. The character 一 (yī) means 'one', and 串 (chuàn) originally depicts objects threaded on a skewer or string; as a measure word, it emphasizes linear, connected arrangement. It’s used for countable nouns where items appear in a chain, cluster, or series.

This phrase commonly appears with objects such as grapes, sausages, keys, firecrackers, or even abstract groupings like jokes or excuses—but only when the speaker wishes to highlight their linked, sequential, or repetitive nature. Unlike generic measure words like 个 (gè), 串 carries a vivid visual and tactile sense of connection. It’s neutral in register and widely used in both spoken and written Mandarin, especially in descriptive or everyday contexts.