reunion vs conjugation

reunion and conjugation both are nouns.

Word	Noun	Adjective	Verb	Adverb
reunion	Yes	No	No	No
conjugation	Yes	No	No	No

As nouns, conjugation is a hypernym of reunion; that is, conjugation is a word with a broader meaning than reunion:

Other hypernyms of reunion include jointure, unification, union, uniting.

reunion (noun)	conjugation (noun)
the act of coming together again	the act of pairing a male and female for reproductive purposes
a party of former associates who have come together again	the act of making or becoming a single unit
	a class of verbs having the same inflectional forms
	the complete set of inflected forms of a verb
	the inflection of verbs
	the state of being joined together