illustreEtymologyFrom Middle French illustre (French illustre), from Latin illūstris (“bright, shining, brilliant, lustrous; clear, lucid; illustrious, distinguished, famous”), from illūstrō (“to illustrate”).adjSynonym of illustrious.verbTo illuminate (something).“But, as the Phœnix on my Front doth gliſter, / Thou ſhalt the Finials of my Frame illuſtre.”To make (someone) illustrious.