Eilyn sits next to 5 phonetic neighbors — Eileen, Aileen, and Aislinn are the closest matches by sound. Most share Eilyn's Irish-rooted cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"bright, shining light"
"noble and devoted to God (possible interpretation)"
"gift of grace, divine favor"
"night beauty"
"beautiful, soft"
"rock (alternative etymology)"
"variant of Larissa, city in Greece"
"cherry tree or fruit"
"branch, vine tendril"
"wise protector"
"garden, vineyard"
"dark-haired, dark warrior"
"Mary + Lynn (lake)"
"priests meadow or clearing"
"grace, favor"
"son of the right hand (via Benjamin)"
"the heavens, celestial realm"
"absorbed in divine glory (Punjabi variant)"
"like unto God"
"praised, one who is praised"
"from the hollow, hollow dweller"
Similar sound: These names share phonetic patterns with Eilyn — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Greek/Irish origins, giving them the same cultural heritage as Eilyn.
Rhythm: Eilyn is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.