dithyramb vs written material

dithyramb and written material both are nouns.

Word	Noun	Adjective	Verb	Adverb
dithyramb	Yes	No	No	No
written material	Yes	No	No	No

As nouns, written material is a hypernym of dithyramb; that is, written material is a word with a broader meaning than dithyramb:

dithyramb: a wildly enthusiastic speech or piece of writing
written material: the work of a writer; anything expressed in letters of the alphabet (especially when considered from the point of view of style and effect)

Other hypernyms of dithyramb include piece of writing, writing, address, speech.

dithyramb (noun)	written material (noun)
(ancient Greece) a passionate hymn (usually in honor of Dionysus)	the work of a writer; anything expressed in letters of the alphabet (especially when considered from the point of view of style and effect)
a wildly enthusiastic speech or piece of writing