illustration vs illustrate

illustration is a noun but illustrate is not a noun.

Word	Noun	Adjective	Verb	Adverb
illustration	Yes	No	No	No
illustrate	No	No	Yes	No

illustration (noun)	illustrate (noun)
a visual representation (a picture or diagram) that is used to make some subject more pleasing or easier to understand
an item of information that is typical of a class or group
artwork that helps make something clear or attractive
showing by example

illustration (verb)	illustrate (verb)
	clarify by giving an example of
	depict with an illustration
	supply with illustrations