gentleness vs gradualness

gentleness and gradualness both are nouns.

Word	Noun	Adjective	Verb	Adverb
gentleness	Yes	No	No	No
gradualness	Yes	No	No	No

As nouns, gentleness and gradualness are synonyms defined as:

gentleness and gradualness: the property possessed by a slope that is very gradual

gentleness (noun)	gradualness (noun)
acting in a manner that is gentle and mild and even-tempered	the quality of being gradual or of coming about by gradual stages
the property possessed by a slope that is very gradual	the property possessed by a slope that is very gradual