haste vs hastiness

haste and hastiness both are nouns.

Word	Noun	Adjective	Verb	Adverb
haste	Yes	No	No	No
hastiness	Yes	No	No	No

As nouns, haste and hastiness are synonyms defined as:

Other synonyms of haste include hurriedness, hurry, precipitation.

haste (noun)	hastiness (noun)
the act of moving hurriedly and in a careless manner	hasty impulsiveness
overly eager speed (and possible carelessness)	overly eager speed (and possible carelessness)
a condition of urgency making it necessary to hurry