hendiadys vs rhetorical device

hendiadys and rhetorical device both are nouns.

Word	Noun	Adjective	Verb	Adverb
hendiadys	Yes	No	No	No
rhetorical device	Yes	No	No	No

As nouns, rhetorical device is a hypernym of hendiadys; that is, rhetorical device is a word with a broader meaning than hendiadys:

hendiadys: use of two conjoined nouns instead of a noun and modifier
rhetorical device: a use of language that creates a literary effect (but often without regard for literal significance)

hendiadys (noun)	rhetorical device (noun)
use of two conjoined nouns instead of a noun and modifier	a use of language that creates a literary effect (but often without regard for literal significance)