cluster vs flock

cluster and flock both are nouns.

Word	Noun	Adjective	Verb	Adverb
cluster	Yes	No	Yes	No
flock	Yes	No	Yes	No

As verbs, cluster and flock are synonyms defined as:

Other synonyms of cluster include clump, constellate.

cluster (noun)	flock (noun)
a grouping of a number of similar things	a group of birds
	a group of sheep or goats
	a church congregation guided by a pastor
	an orderly crowd
	(often followed by `of') a large number or amount or extent

cluster (verb)	flock (verb)
gather or cause to gather into a cluster	come together as in a cluster or flock
come together as in a cluster or flock	move as a crowd or in a group