A modern invented name, possibly a variant of Kaylee.
Jeily is a contemporary American creation without a single established etymological root. It likely evolved as a phonetic variant of names like Kaylee or Hailey, or as a combination of the 'J' initial with the popular 'eily' suffix. Because of its modern origin, it lacks a traditional historical meaning.
Less common today
Jeily isn't in the latest US Top 1000. It last peaked at #5,914 in 2011.
US births per 5-year period, 1990βpresent (SSA data).