WordWeb Online

1. A grouping of a number of similar things
   - bunch, clump, cluster

1. Come together as in a cluster or flock
   "The poets cluster in this town every summer";
   - constellate, flock, clump
    
2. Gather or cause to gather into a cluster
   "She clustered her fingers into a fist";
   - bunch, bundle, clump

Derived forms: clusterings

Type of: agglomeration, assemble, foregather, forgather, form, gather, meet

Encyclopedia: Clustering