noun a number of things of the same kind growing together; a bunch.
2. cluster ·vt to collect into a cluster or clusters; to gather into a bunch or close body.
3. cluster ·noun a number of individuals grouped together or collected in one place; a crowd; a mob.
4. cluster ·vi to grow in clusters or assemble in groups; to gather or unite in a cluster or clusters.
5. cluster ·noun a number of similar things collected together or lying contiguous; a group; as, a cluster of islands.