Kay sits next to 3 phonetic neighbors — Kai, Cay, and Kae 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
"rejoice; pure"
"quality, excellence of character"
"heroic, on a grand scale"
"remembered by the Lord"
"may God protect"
"dweller by the hedged forest"
"raven sword, renowned with the blade"
"gift of healing"
"good, excellent + blue"
"little dark one"
"brave traveler"
"hill, burial mound"
"fictional Fire Lord, invented name"
"modern invented name"
"something deserved, virtue"
"date palm, palm tree"
"God has remembered"
"from the Afton river"
"nothing (informal)"
"strong-willed warrior"
Similar sound: These names share phonetic patterns with Kay — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Latin 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.