Anglicized spelling of Síle, the Irish Gaelic form of Cecily. This name has become so common and widespread that it is hardly felt to be Irish any longer. In Australia since the 19th century it has been a slang generic term for any woman.
English (of Norman origin): habitational name from a lost place, of uncertain location, named in Anglo-Norman French as mesnil Warin ‘domain of Warin’ (see Waring). The surname has had a large number of variant spellings; it is normally pronounced ‘Mannering’.