CLUSTER, noun

1. A bunch; a number of things of the same kind growing or joined together; a knot; as a cluster of raisins.

2. A number of individuals or things collected or gathered into a close body; as a cluster of bees; a cluster of people.

3. A number of things situated near each other; as a cluster of governments in Italy.

CLUSTER, verb intransitive

1. To grow in clusters; to gather or unite in a bunch, or bunches; as, clustering grapes.

2. To form into flakes; as, clustering snow.

3. To collect into flocks or crowds.

CLUSTER, verb transitive To collect into a bunch or close body.