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"
"descendant of Freyr, little lord"
"one who serves and learns"
"fictional villain name from The Witcher"
"iron strong"
"freedom, rights document"
"ancestor's relic, heir of ancestors"
"My God is He"
"lion"
"earnest effort, striving"
"one who grows, rises, flourishes"
"possibly derived from jet (black gemstone) or speed"
"creative combination"
"From the boar meadow; ever-lasting meadow"
"to create; creation"
"bearer of Christ"
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.