Keir sits next to 5 phonetic neighbors — Kier, Kiir, and Ciarán are the closest matches by sound. Most share Keir's Scottish cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"dark one, dark-complexioned"
"dove"
"A dark image or form following a person or object"
"son of the gray-haired one"
"red-haired king"
"He whom Yahweh remembered"
"little red one"
"son of Roderick"
"dark, full; complete darkness"
"fair-haired one"
"of the elm tree, smooth stream"
"wolf cub"
"resolute protector, determined guardian"
"wealthy protector"
"son of Copen (geographic surname)"
"son of Alexander (defender of men)"
"westward direction"
"strong, firm, enduring"
Similar sound: These names share phonetic patterns with Keir — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Scottish Gaelic ciar origins, giving them the same cultural heritage as Keir.
Rhythm: Keir is a 1-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.