Cailyn sits next to 4 phonetic neighbors — Kaylyn, Kaelyn, and Caitlin are the closest matches by sound. Most share Cailyn's Irish-rooted cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"pure"
"courageous, valiant"
"adventurer, seafarer"
"work, industrious"
"gift, wealthy (from Jesse)"
"sand-colored, from the sand"
"dahlia flower"
"graceful, favored"
"little king, royal one"
"crooked nose, bent nose"
"strong, honorable pool"
"pure (via Katherine)"
"Christian woman"
"made of gold, golden-colored"
"variant of Kira, possibly meaning sun or throne"
"innocent, gentle one"
"joy, happiness, gladness"
"his gift"
"bright, shining one"
"life, living one"
Similar sound: These names share phonetic patterns with Cailyn — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Greek via Irish origins, giving them the same cultural heritage as Cailyn.
Rhythm: Cailyn is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.