Joan sits next to 3 phonetic neighbors — Jean, June, and Jane are the closest matches by sound. Most share Joan's English-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"God is gracious"
"black gemstone with white bands"
"sparkling, bright as crystal"
"pledged to God, God is my oath"
"lovable, grace and beauty"
"descendant of Rian"
"welcome, greetings"
"Tynni's clearing, woodland meadow"
"symbol of enduring affection and daily remembrance"
"dedicated to Mars"
"judged, vindicated"
"pure (from Catherine via Caitlin)"
"sorrow, regret"
"maiden, young girl"
"spring goddess (Persephone's maiden name)"
"wisdom"
"noble, of noble birth"
"graceful, swift"
"moon"
Similar sound: These names share phonetic patterns with Joan — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Hebrew origins, giving them the same cultural heritage as Joan.
Rhythm: Joan is a 1-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.