Cluster \Clus"ter\, v. i. [imp. & p. p. Clustered; p. pr. & vb. n. Clustering.]

To grow in clusters or assemble in groups; to gather or unite in a cluster or clusters.

His sunny hair Cluster'd about his temples, like a god's. --Tennyson.

The princes of the country clustering together. --Foxe.

Source: Webster's Revised Unabridged Dictionary (1913)