Mcclain sits next to 4 phonetic neighbors — McLean, Mclane, and McCain are the closest matches by sound. Most share Mcclain's Irish-rooted cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"son of the servant of Saint John"
"rose"
"He is my God"
"appointed by God"
"chosen, selected, picked out"
"settlement of Jay, from Jay + ton"
"from the open moorland"
"rue plant, bitter herb"
"son of Daw (David), beloved son"
"Mardi Gras parade organization"
"valley, dale"
"thunder warrior, Thor's strength"
"light of God"
"scholar (via Skylar)"
"strawberry grower"
"of God, divine man"
"healer (if from Jason)"
"modern coined name, possibly hillside light"
"messenger goddess"
"modern creative construction"
"God is gracious"
Similar sound: These names share phonetic patterns with Mcclain — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Scottish Gaelic Mac Gille Eathain origins, giving them the same cultural heritage as Mcclain.
Rhythm: Mcclain is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.