promptitude vs speediness

promptitude and speediness both are nouns.

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

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

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

promptitude (noun)	speediness (noun)
the characteristic of doing things without delay	a rate that is rapid