expeditiousness vs speediness

expeditiousness and speediness both are nouns.

Word	Noun	Adjective	Verb	Adverb
expeditiousness	Yes	No	No	No
speediness	Yes	No	No	No

As nouns, speediness is a hypernym of expeditiousness; that is, speediness is a word with a broader meaning than expeditiousness:

Other hypernyms of expeditiousness include celerity, quickness, rapidity, rapidness.

expeditiousness (noun)	speediness (noun)
the property of being prompt and efficient	a rate that is rapid