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"
"clear ice, rock crystal, quartz"
"noble, of noble lineage"
"modern phonetic name, variant of Braylee"
"honey, sweet"
"gatekeeper, doorman"
"grey lady"
"pure, unblemished"
"worthy, deserved"
"middle of the week"
"descendant of the dark challenger"
"star-maiden, goddess of justice"
"modern invented combination name"
"beautiful, yielding to prayer"
"praised, he will be praised"
"grace, the gracious one"
"speech, utterance"
"God is gracious"
"of the air"
"exalted, high, heavenly"
"king's meadow or island"
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.