speech vs dithyramb

speech and dithyramb both are nouns.

Word	Noun	Adjective	Verb	Adverb
speech	Yes	No	No	No
dithyramb	Yes	No	No	No

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

speech (noun)	dithyramb (noun)
the mental faculty or power of vocal communication	(ancient Greece) a passionate hymn (usually in honor of Dionysus)
(language) communication by word of mouth	a wildly enthusiastic speech or piece of writing
the act of delivering a formal spoken communication to an audience
words making up the dialogue of a play
a lengthy rebuke
the exchange of spoken words
your characteristic style or manner of expressing yourself orally
something spoken