Irish and Scottish Gaelic form of Cecilia [q.v.] or Celia, from a Roman family name, from Latin "blind".

The Scottish form is unaccented: Sile and may be found as Sileas or Silis.

Síle/Sile may be Anglicized as Sheila, Shelagh or Sheelagh.

The Latin version, in old documents, is Caelia.