illustrate vs decorate

illustrate and decorate both are verbs.

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

As verbs, decorate is a hypernym of illustrate; that is, decorate is a word with a broader meaning than illustrate:

Other hypernyms of illustrate include adorn, beautify, embellish, grace, ornament.

illustrate (verb)	decorate (verb)
clarify by giving an example of	provide with decoration
depict with an illustration	make more attractive by adding ornament, colour, etc.
supply with illustrations	award a mark of honor, such as a medal, to
	be beautiful to look at