Cahill is a name of Irish origin. In Irish, It is the anglicized version of the Gaelic "Ã Cathail" meaning "descendant of Cathal." "Cathal" consists of two parts: "cath" means battle; the second could be "val" , so that the name as a whole meant "battle ruler" or "strong in battle", or it could be "all" , so that the name as a whole meant "great warrior". The surname may refer to: