ode vs epithalamium

ode and epithalamium both are nouns.

Word	Noun	Adjective	Verb	Adverb
ode	Yes	No	No	No
epithalamium	Yes	No	No	No

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

Other hyponyms of ode include Horatian ode, Sapphic ode, Pindaric, Pindaric ode, choral ode.

ode (noun)	epithalamium (noun)
a lyric poem with complex stanza forms	an ode honoring a bride and bridegroom