gradient vs grade

gradient and grade both are nouns.

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

As nouns, grade is a hyponym of gradient; that is, grade is a word with a more specific, narrower meaning than gradient:

gradient: the property possessed by a line or surface that departs from the horizontal
grade: the gradient of a slope or road or other surface

Other hyponyms of gradient include pitch, rake, slant, abruptness, precipitousness, steepness, gentleness, gradualness.

gradient (noun)	grade (noun)
the property possessed by a line or surface that departs from the horizontal	a variety of cattle produced by crossbreeding with a superior breed
a graded change in the magnitude of some physical quantity or dimension	a position on a scale of intensity or amount or quality
	the gradient of a slope or road or other surface
	the height of the ground on which something stands
	a number or letter indicating quality (especially of a student's performance)
	a degree of ablaut
	a body of students who are taught together
	one-hundredth of a right angle
	a relative position or degree of value in a graded group

gradient (verb)	grade (verb)
	determine the grade of or assign a grade to
	assign a rank or rating to
	assign a grade or rank to, according to one's evaluation
	level to the right gradient