meeting vs caucus

meeting and caucus both are nouns.

Word	Noun	Adjective	Verb	Adverb
meeting	Yes	No	No	No
caucus	Yes	No	Yes	No

As nouns, caucus is a hyponym of meeting; that is, caucus is a word with a more specific, narrower meaning than meeting:

meeting (noun)	caucus (noun)
the social act of assembling for some common purpose	a closed political meeting
the act of joining together as one
a casual or unexpected convergence
a formally arranged gathering
a small informal social gathering
a place where things merge or flow together (especially rivers)

meeting (verb)	caucus (verb)
	meet to select a candidate or promote a policy