Combination of Ella and the suffix -syn
Ellasyn is a modern American invention, likely created by blending the popular vintage name Ella with the trendy '-syn' or '-synne' suffix. It follows the pattern of names like Addison or Emerson but maintains a more feminine feel. Because it is a contemporary coinage, it does not have a singular historical etymology beyond its component parts.
Less common today
Ellasyn isn't in the latest US Top 1000. It last peaked at #3,301 in 2011.
US births per 5-year period, 1990βpresent (SSA data).