Pure; slender
Kayly is a modern phonetic variation of Kaylee or Caelie. It likely derives from the Greek word 'katharos' meaning pure, or the Irish surname O'Caollaidhe, which refers to a descendant of the slender one.
Less common today
Kayly isn't in the latest US Top 1000. It last peaked at #4,357 in 2004.
US births per 5-year period, 1990βpresent (SSA data).