increment vs incremental

increment is a noun but incremental is not a noun.

Word	Noun	Adjective	Verb	Adverb
increment	Yes	No	No	No
incremental	No	Yes	No	No

increment (noun)	incremental (noun)
the amount by which something increases
a process of becoming larger or longer or more numerous or more important

increment (adjective)	incremental (adjective)
	increasing gradually by regular degrees or additions