Eirnin sits next to 4 phonetic neighbors — Eirinn, Arnan, and Ernin are the closest matches by sound. Most share Eirnin's Irish-rooted cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"little iron one, iron-hearted"
"possibly derived from jet (black gemstone) or speed"
"earnest effort, striving"
"ancestor's relic, heir of ancestors"
"young attendant, page boy"
"creative combination"
"winding stream, crooked well"
"bright one, sunlit"
"one who grants charters, document giver"
"iron strong"
"He is my God"
"modern American coinage, unique creation"
"From the boar meadow; ever-lasting meadow"
"one who grows, rises, flourishes"
"lion"
"to create; creation"
Similar sound: These names share phonetic patterns with Eirnin — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Old Irish iarn + -ín origins, giving them the same cultural heritage as Eirnin.
Rhythm: Eirnin is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.