Kelsy sits next to 5 phonetic neighbors — Kelsey, Chelsea, and Kelsie are the closest matches by sound. Most share Kelsy's English-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"ship island"
"the moon (by association with Artemis)"
"soldier"
"gift of God"
"beautiful, honest (in Japanese tradition)"
"sky-colored, blue"
"son of James"
"bright, shining"
"calm, gentle waters"
"pearl"
"night, dark beauty (if from Leila)"
"Lord have mercy (prayer refrain)"
"modern creative name; bright, graceful one"
"leek settlement, meadow town"
"black, dark hardwood"
"Diana (goddess of the hunt)"
"moon (from Roman goddess Luna)"
"slender, fair"
"courageous, valiant"
"land of the lochs, lake land"
Similar sound: These names share phonetic patterns with Kelsy — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Old English (Cenel + eg) origins, giving them the same cultural heritage as Kelsy.
Rhythm: Kelsy is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.