(From card games in which certain cards, often the joker, can act as any other card) A special character or character sequence which maTChes any character in a string comparison, like ellipsis ("...") in ordinary written text. In Unix filenames ' ?' maTChes any single character and ' *' maTChes any zero or more characters. In {regular expressions}, ' .' maTChes any one character and "[...]" maTChes any one of the enclosed characters. See also Backus-Naur Form. (1997-07-16)