Adelaide sits next to 3 phonetic neighbors — Adeline, Adele, and Adaline are the closest matches by sound. Most share Adelaide's English-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"noble kind, of noble birth"
"flat plain"
"most holy"
"white hero"
"heavenly, of the sky"
"song, tune, music"
"swift, agile"
"sea of bitterness"
"beautiful one, noble"
"joy, music"
"patron of musicians, derived from Latin caecus meaning blind"
"honor, honorable"
"elm tree"
"oath of God"
"descendant of Riagan"
"red king; red-haired ruler"
"light, illumination"
"torch, fire"
"precious gem, pearl of great price"
"jewel, bud"
Similar sound: These names share phonetic patterns with Adelaide — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Old High German origins, giving them the same cultural heritage as Adelaide.
Rhythm: Adelaide is a 4-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.