diction vs formulation

diction and formulation both are nouns.

Word	Noun	Adjective	Verb	Adverb
diction	Yes	No	No	No
formulation	Yes	No	No	No

As nouns, formulation is a hypernym of diction; that is, formulation is a word with a broader meaning than diction:

Other hypernyms of diction include expression.

diction (noun)	formulation (noun)
the manner in which something is expressed in words	inventing or contriving an idea or explanation and formulating it mentally
the articulation of speech regarded from the point of view of its intelligibility to the audience	the style of expressing yourself
	a substance prepared according to a formula