flock vs forgather

flock is a noun but forgather is not a noun.

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

As verbs, forgather is a hypernym of flock; that is, forgather is a word with a broader meaning than flock:

Other hypernyms of flock include assemble, foregather, gather, meet.

flock (noun)	forgather (noun)
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

flock (verb)	forgather (verb)
come together as in a cluster or flock	collect in one place
move as a crowd or in a group