wildcard

noun

1. A character that takes the place of any other character or string that is not known or specified.

   “1968, Digital Equipment Corporation, VAX/VMS 319(5864), page 751, Section 2.1.2 Using Wildcard Characters A wildcard character is a symbol that you can use with many DCL commands to apply the command to several files at once, rather than specifying each file individually.”

   “If the character * is acting as a wildcard, then the pattern a*m matches each of the words amalgam, atom and alum.”

2. An uncontrolled or unpredictable element.

   “There are several technical wildcards, such as how the larger battery packs--four times larger than those of the Prius--will withstand the rigors of city driving, […]”

3. An element, often deliberately concealed, which is withheld for contingency.
4. (alt-of, alternative)Alternative form of wild card.

   “German wildcard Sabine Lisicki conquered her nerves to defeat France's Marion Bartoli and take her amazing Wimbledon run into the semi-finals.”

5. A letter or symbol that substitutes for a generic or poorly identified sound, for example capital C for any or some consonant, or capital V for any or some vowel.

verb

1. To replace or supplement with a wildcard character to allow matching against a range of possible values.

   “The unfortunate consequence is that document elements cannot be wildcarded because a schema needs to provide a closed list of possible document elements.”