IPA: //ˈsʌmp.tʃu.əs.nəs//
KK: /ˈsʌmp.tʃu.əs.nəs/
The quality of being luxurious, rich, and extravagant in appearance or style.
The sumptuousness of the banquet left the guests in awe.
Sumptuousness → It is formed from "sumptuarius" (from Latin, meaning costly or extravagant) and the suffix "-ness" (meaning the state or quality of). The word "sumptuousness" refers to the quality of being luxurious or extravagant in appearance or style.
Think of something that is 'costly' or 'extravagant' — that's what sumptuousness means, reflecting a state of luxury.