Rihanna sits next to 4 phonetic neighbors — Rhiannon, Brianna, and Arianna are the closest matches by sound. Most share Rihanna's Arabic-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"great queen"
"beautiful, graceful"
"princess, noblewoman"
"land of the Welsh, Wales"
"dark-eyed one, hawk-eyed"
"wave"
"jasmine flower"
"noble, honored"
"blissful, from Elysium"
"singer"
"conflict, strife"
"Jay + lake (modern American coinage)"
"my God is abundance"
"Geirr's island"
"God is gracious"
"beautiful, radiant"
"fair one from the clearing"
"lion strength, brave as a lion"
"gentle, beautiful"
"home ruler (as short for Harriet/Henrietta)"
Similar sound: These names share phonetic patterns with Rihanna — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Celtic via Welsh origins, giving them the same cultural heritage as Rihanna.
Rhythm: Rihanna is a 3-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.