paean vs congratulations

paean and congratulations both are nouns.

Word	Noun	Adjective	Verb	Adverb
paean	Yes	No	No	No
congratulations	Yes	No	No	No

As nouns, congratulations is a hypernym of paean; that is, congratulations is a word with a broader meaning than paean:

Other hypernyms of paean include extolment, kudos, praise.

paean (noun)	congratulations (noun)
a formal expression of praise	an expression of approval and commendation
(ancient Greece) a hymn of praise (especially one sung in ancient Greece to invoke or thank a deity)