Kay sits next to 4 phonetic neighbors — Kay, Mae, and Fay are the closest matches by sound. Most share Kay's English-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"pure, clean"
"to know, to be wise"
"from Milan, of the plain"
"beauty, grace"
"twilight, between day and night"
"fair hero"
"little rock, harmony"
"divine, of the celestial realm"
"singer, melodious"
"new beginning, new light"
"fair-haired hero"
"dawn, the bright place"
"God is abundance"
"pure, free (khalī in Arabic)"
"hay meadow, hay clearing"
"heavenly, sky"
"bright, shining light"
"place of camas, sacred meadow"
"pledge, noble oath"
"royal child of heaven"
"rich, powerful"
Similar sound: These names share phonetic patterns with Kay — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Greek via Katherine origins, giving them the same cultural heritage as Kay.
Rhythm: Kay is a 1-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.