Kellen sits next to 4 phonetic neighbors — Kellan, Kell, and Helen are the closest matches by sound. Most share Kellen's Irish-rooted cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"slender, narrow"
"from Mauritania"
"crooked mouth, wry-mouthed"
"acquired, possessed"
"boisterous, spirited, lively"
"free man"
"beloved companion"
"drop, teardrop"
"sea"
"YHWH has been gracious"
"olive tree"
"beloved of God"
"who is like God"
"my God is salvation"
"church official"
"goodness of Yahweh"
"one who catches fish"
"to rejoice, joyful"
"manly, brave"
"Trent's town, settlement on the Trent"
"permanent, steadfast"
Similar sound: These names share phonetic patterns with Kellen — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Irish Gaelic 'caol' origins, giving them the same cultural heritage as Kellen.
Rhythm: Kellen is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.