Early 20th century. From alairy, an expression with many variants and uncertain sense and origin, forming part of the refrain of the rhyme traditionally sung or chanted (in various versions) while playing this game. It has been argued that this expression is related to aliry, with allusion to the movement of leg over the ball that usually accompanies the utterance of this word in many versions of the ball game, although this explanation is not straightforward in terms of chronology or semantics and confirmatory evidence is lacking.