Jay sits next to 4 phonetic neighbors — Ray, Kay, and Trey are the closest matches by sound. Most share Jay's English-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"to rejoice, joyful"
"mill worker, grain grinder"
"the victorious (Arabic city name)"
"messenger of God"
"one who bails, deliverer"
"one who lives near a lane"
"praiseworthy, laudable"
"ancient, enduring"
"gift of Yahweh"
"sea-born, born of the sea"
"lord, master"
"army man, soldier"
"raven"
"healer (from Greek Jason)"
"wave, abundant, learned"
"sorrowful (folk etymology via French)"
"kingly, of royal blood"
"lover of horses"
"from the green valley"
"invented name, possibly evoking sky"
Similar sound: These names share phonetic patterns with Jay — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Latin (Gaius) origins, giving them the same cultural heritage as Jay.
Rhythm: Jay is a 1-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.