Alastair sits next to 4 phonetic neighbors — Alistair, Alister, and Alexander are the closest matches by sound. Most share Alastair's Scottish cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"defender of men"
"beloved of the sea"
"village by the street"
"sword"
"beauty, adornment, grace"
"settlement by the bridge"
"Yahweh has shown favor"
"Dack's settlement"
"God has given"
"help, strength"
"wise one, seer"
"man of Rome"
"victory of the people"
"my people"
"reed clearing"
"darling, treasured one"
"unity, excellence, number one"
"Isle of Skye, Scotland"
"modern invented name with no fixed meaning"
"rock, harbor"
Similar sound: These names share phonetic patterns with Alastair — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Greek via Scottish Gaelic origins, giving them the same cultural heritage as Alastair.
Rhythm: Alastair is a 3-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.