According to vocabulary.com, illustrious is an adjective that means widely known and esteemed or having glory. Illustriousness is the noun form of illustrious.
- Everyone applauded when she walked into the room and congratulated her on her illustrious career as an actress.
- The company made the right decision by choosing him as their illustrious leader.
- You shouldn’t apologize for having an illustrious career.
- Some believe those with illustrious careers are unapproachable.
Some synonyms include distinguished, eminent, exalted, and famed.