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’.
German and Jewish (Ashkenazic): occupational name for a tailor, literally ‘cutter’, from Middle High German snīder, German Schneider, Yiddish shnayder. The same term was sometimes used to denote a woodcutter. This name is widespread throughout central and eastern Europe.