Gracious
Eain is a rare phonetic spelling variant of Ian, which is the Scottish Gaelic form of John. It ultimately derives from the Hebrew name Yochanan, meaning 'God is gracious.'
Less common today
Eain isn't in the latest US Top 1000. It last peaked at #7,910 in 2006.
US births per 5-year period, 1990βpresent (SSA data).