Where does “illustriously” come from?
illustriously (English) comes from English illustrious, from Latin illūstris, from Latin illustro, from Latin lūstrō, from Latin lūstrum, from Old Latin loustrom, from Proto-Indo-European lewkstrom, from Proto-Indo-European lewk- — bright; to shine; to see.
illustriously (English): In an illustrious manner
Ancestry of “illustriously”, step by step