IPA: /ˈwɛlθɪli/
KK: /ˈwɛlθɪli/
In a manner that shows great wealth or affluence.
They lived wealthily in a large mansion with luxurious amenities.
Wealthily → It is formed from "wealth" (from Old English *wela*, meaning well-being or prosperity) and "-ily" (a suffix forming adverbs, meaning in a manner of). The word "wealthily" means in a manner that pertains to wealth or prosperity.
Think of 'wealth' as a state of prosperity, and remember that 'wealthily' describes how one behaves or lives in a prosperous manner.