clustering

(noun) a grouping of a number of similar things. Synonyms: bunch, clump, cluster. Examples: "A bunch of trees." "A cluster of admirers."

(verb) come together as in a cluster or flock. Synonyms: cluster, constellate, flock, clump. Examples: "The poets constellate in this town every summer."

(verb) gather or cause to gather into a cluster. Synonyms: bunch, bunch up, bundle, cluster, clump. Examples: "She bunched her fingers into a fist."