immediacy vs speediness

immediacy and speediness both are nouns.

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

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

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

immediacy (noun)	speediness (noun)
the quickness of action or occurrence	a rate that is rapid
lack of an intervening or mediating agency
immediate intuitive awareness