Milly sits next to 4 phonetic neighbors — Millie, Molly, and Lily are the closest matches by sound. Most share Milly's English-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"strength in work, industrious"
"eagle"
"diminutive of Dorothy, beloved pet name"
"descendant of Raghallach"
"farmer, earth-worker"
"symbol of wisdom and prosperity"
"grace combined with woodland clearing"
"my father is joy"
"cheerful, joyful"
"hardest substance, precious gemstone"
"vast, empty landscape"
"pinkish-orange color of the sea"
"sun, bright"
"path, road (Old English)"
"clover plant"
"meadow near the hill"
"everything is all right; peaceful harmony"
"land of the Vitali/young cattle"
"light, illuminated"
"lake, pool"
"rye meadow, island clearing"
Similar sound: These names share phonetic patterns with Milly — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Germanic origins, giving them the same cultural heritage as Milly.
Rhythm: Milly is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.