Originally an Anglicized form of the ancient Irish male name Ceallach. It is now very widely used in the English-speaking world, mainly as a girl's name. This is a transferred use of the surname Ó Ceallaigh ‘descendant of Ceallach’.
English: habitational name from the district so called near Liverpool, consisting of Uplitherland and Downlitherland. The place name is derived from Old Norse hlíðar, genitive of hlíð ‘slope’ + land ‘land’.