meeting vs congress

meeting and congress both are nouns.

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

As nouns, meeting and congress are synonyms defined as:

meeting and congress: the social act of assembling for some common purpose

Other synonyms of meeting include coming together.

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

meeting (noun)	congress (noun)
the social act of assembling for some common purpose	the social act of assembling for some common purpose
the act of joining together as one	a meeting of elected or appointed representatives
a casual or unexpected convergence	a national legislative assembly
a formally arranged gathering
a small informal social gathering
a place where things merge or flow together (especially rivers)