Casey sits next to 3 phonetic neighbors — Kasey, Lacey, and Macy are the closest matches by sound. Most share Casey's Irish-rooted cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"mounted warrior, horseman"
"short form of Jason, the healer"
"son of the grey-haired one"
"beloved son"
"firm foundation"
"priest's town, priestly settlement"
"son of God's grace"
"son of Stephen, crown bearer"
"superlative of magnus (great)"
"priest"
"house builder, craftsman"
"eagle"
"strength, dominance"
"hillock, small hill"
"fearless, not cowardly"
"to live, to dwell"
"son of Karr"
"divine messenger"
Similar sound: These names share phonetic patterns with Casey — similar vowel sounds, consonant clusters, or rhythm.
Rhythm: Casey is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.