Delta sits next to 4 phonetic neighbors — Della, Delia, and Zelda are the closest matches by sound. Most share Delta's Greek-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"River mouth, fertile land"
"noble and gentle"
"earth, land"
"pearl"
"of the sea; bitter; pearl"
"to rejoice, exultation"
"god, divine spirit"
"my God is abundance"
"ruler of men"
"of the air"
"creative blend of Ja- prefix and Leah (weary)"
"grace, eternal beauty"
"son of David"
"excellence, mastery (from Ace) + lake/waterfall (from Lynn)"
"bailiff, law officer"
"of noble kind, noble birth"
"From the coast"
"dear little Ana, gracious one"
"wealthy"
"God is gracious"
"from the sky, heavenly"
Similar sound: These names share phonetic patterns with Delta — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Greek origins, giving them the same cultural heritage as Delta.
Rhythm: Delta is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.