Lucile sits next to 4 phonetic neighbors — Lucille, Lucille, and Lucinda are the closest matches by sound. Most share Lucile's French-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"light, illumination"
"one from the hollow or nook"
"from Britain; British woman"
"clearing in the hazel grove"
"harmony, freedom from conflict"
"hay meadow, hay clearing"
"pretty, beautiful, tender"
"respectable, virtuous"
"sky, heaven"
"joyful, happy, rejoicing"
"heavenly darkness (if Hawaiian-Greek blend)"
"short form of Josephine"
"fair and slender girl"
"silver one, the bright"
"poetic, expressive of direct emotion (modern English sense)"
"victorious one"
"descendant of the king"
"exalted by God"
"lead-colored, blue-gray"
"soft split-grain leather"
"oak tree"
Similar sound: These names share phonetic patterns with Lucile — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Latin origins, giving them the same cultural heritage as Lucile.
Rhythm: Lucile is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.