verb uk / ˈklʌstə r/ us cluster around, round, together, etc. to form a close group: The meaning of CLUSTER is a number of similar things that occur together. How to use cluster in a sentence. Cluster definition: A group of the same or similar elements gathered or occurring closely together; a bunch. Define cluster . cluster synonyms, cluster pronunciation, cluster translation, English dictionary definition of cluster . n. 1. A group of the same or similar elements gathered or occurring closely together; a bunch: "She held out her hand, a small tight cluster of fingers" ....
