聚集 is a verb meaning 'to gather' or 'to congregate', describing the action of people, animals, or things coming together in one place. Both characters contribute to the meaning: 聚 (jù) means 'to assemble' or 'to collect', and 集 (jí) means 'to gather' or 'to collect' — together they form a compound with strong emphasis on collective movement toward a shared location. It often implies intentionality or natural tendency, especially in contexts like animal behavior, crowd formation, or social events.

This word is commonly used in both formal and informal settings, though it tends to sound slightly more formal or literary than simpler alternatives like 来 (lái) or 到一起 (dào yīqǐ). It frequently appears in news reports, ecological descriptions, and everyday speech when referring to visible groupings — for example, birds gathering before migration or protesters assembling in a square.