gentleness vs gradient

gentleness and gradient both are nouns.

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

As nouns, gradient is a hypernym of gentleness; that is, gradient is a word with a broader meaning than gentleness:

gentleness: the property possessed by a slope that is very gradual
gradient: the property possessed by a line or surface that departs from the horizontal

Other hypernyms of gentleness include slope.

gentleness (noun)	gradient (noun)
acting in a manner that is gentle and mild and even-tempered	the property possessed by a line or surface that departs from the horizontal
the property possessed by a slope that is very gradual	a graded change in the magnitude of some physical quantity or dimension