flock vs cluster

flock and cluster both are nouns.

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

As verbs, flock and cluster are synonyms defined as:

Other synonyms of flock include clump, constellate.

flock (noun)	cluster (noun)
a group of birds	a grouping of a number of similar things
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

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