famous vs illustrious

famous and illustrious both are adjectives.

Word	Noun	Adjective	Verb	Adverb
famous	No	Yes	No	No
illustrious	No	Yes	No	No

As adjectives, famous and illustrious are synonyms defined as:

Other synonyms of famous include celebrated, famed, far-famed, notable, noted, renowned.

famous (adjective)	illustrious (adjective)
widely known and esteemed	having or conferring glory
	widely known and esteemed