Illustrious a. : Possessing luster or brightness; brilliant; luminous; splendid.

Illustrious a. : Characterized by greatness, nobleness, etc.; eminent; conspicuous; distinguished.

Illustrious a. : Conferring luster or honor; renowned; as, illustrious deeds or titles.

Example:
How much does Obama winning the Nobel discredit the once Illustrious prize?

Taxonomy
Merriam-Webster Online Dictionary, Dictionary, webster, Word Games, Webster Online Dictionary with audio pronunciations, thesaurus, glossary, english, language, ESL, adjective, Etymology, Latin, illustris, illustrare, brilliantly, dignity, achievements.

Defination from the web:
illustrious from the Merriam-Webster Online Dictionary with audio pronunciations, thesaurus, Word of the Day, and word games. ... Learn more about "illustrious" Learn more about "illustrious" and related topics at Britannica.com. Pronunciation Symbols. Share this entry: ...