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"
"Beauty, grace"
"narrow water crossing"
"little seal"
"wealthy companion"
"manly, brave"
"group, band, team"
"to hold fast, to restrain"
"slender, thin"
"mythical bird of rebirth"
"deer lover, champion warrior"
"modern American coinage, son of Case"
"broad clearing in the woods"
"round hill"
"lotus flower"
"pledge of peace"
"adornment, goodness"
"little star"
"elf counsel, supernatural wisdom"
"people's victory"
"child"
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.