Keiran sits next to 5 phonetic neighbors — Kieran, Kiran, and Caelan are the closest matches by sound. Most share Keiran's Irish-rooted cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"dark one, little dark one"
"from the rocky settlement"
"of the sea, marine"
"great happiness, delight"
"best, excellent"
"ridge settlement"
"zero, the concept of nothing"
"modern invented name variant of Hayden"
"God has heard (via Sam = Samuel)"
"black, swarthy"
"son of James, supplanter"
"dark one, dark water"
"flood tide, abundance"
"God has heard"
"bright-headed"
"dawn, daybreak"
"rising, ascending"
"marked one"
"protector of people"
"flowing river, running water"
"greatest conqueror"
Similar sound: These names share phonetic patterns with Keiran — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Irish origins, giving them the same cultural heritage as Keiran.
Rhythm: Keiran is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.