has been clustering

• present perfect progressive

  present perfect progressive

  Used to describe an action that began in the past, has continued continuously, and is still in progress.

  of cluster (3rd person singular).
  cluster

  noun

  a number of things of the same kind, growing or held together; a bunch.

Related Words

• array
• assemblage
• band
• batch
• bunch
• bundle
• chunk
• clump
• collection
• knot