Prosper sits next to 3 phonetic neighbors — Jasper, Foster, and Chester are the closest matches by sound. Most share Prosper's French-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"to thrive, to succeed, prosperous"
"eagle land"
"patient, persevering"
"highest point in the sky, directly overhead"
"son of Paye/Pace (son of Peace)"
"surname-to-given-name transfer"
"high, enlightened"
"raven, dark one"
"Carl's town or farm"
"son of grace; graceful"
"brave"
"vigorous, energetic ruler"
"liberation, journey"
"round, barrel"
"to conquer"
"flower, flourishing"
"God is with us"
"nickname for Charles"
"dedicated to Mars (god of war)"
"powerful ruler"
"chosen, elected, the elect"
Similar sound: These names share phonetic patterns with Prosper — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Latin origins, giving them the same cultural heritage as Prosper.
Rhythm: Prosper is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.