IPA: /prəˈspɛrəsli/
KK: /prɑː'spɜːrəsli/
In a way that shows success, wealth, or good fortune.
The business grew prosperously, attracting many new customers.
Prosperously → It is formed from "prosperus" (from Latin, meaning fortunate or successful) and the suffix "-ly" (meaning in a manner of). The word "prosperously" means in a manner that is fortunate or successful.
Think of being 'fortunate' ('prosperus') and doing things 'in a manner' ('-ly') that leads to success.