immediacy vs celerity

immediacy and celerity both are nouns.

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

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

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

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