Kilian sits next to 4 phonetic neighbors — Killian, Cillian, and Killean are the closest matches by sound. Most share Kilian's Irish-rooted cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"little church"
"slender and fair"
"earnestness, sincerity"
"flame, fiery one"
"rock, harmony"
"at the holly trees"
"fine, elegant"
"wolf counsel"
"spear ruler (from Gerald)"
"one who pursues"
"battle chieftain (Cerdic interpretation)"
"leader, lord"
"brave in battle"
"warrior, defender"
"God is gracious"
"light, luminous"
"dark warrior"
"may God protect, holder of the heel"
"immortal, eternal"
"watchful"
"from Sebaste"
Similar sound: These names share phonetic patterns with Kilian — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Irish Gaelic origins, giving them the same cultural heritage as Kilian.
Rhythm: Kilian is a 3-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.