Eilish sits next to 4 phonetic neighbors — Elish, Ailis, and Alice are the closest matches by sound. Most share Eilish's Irish-rooted cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"pledged to God"
"hidden, promised"
"war, strife"
"healer"
"crow, raven-haired"
"spirited, dashing, energetic"
"lake, pool"
"rib, side of land"
"God will add"
"born of fire, handsome"
Similar sound: These names share phonetic patterns with Eilish — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Hebrew via Irish origins, giving them the same cultural heritage as Eilish.
Rhythm: Eilish is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.