Definitions
1.nounA human language that has been consciously devised by an individual or a small group, as opposed to having naturally evolved as part of a culture like a natural language.
2.nounAny language, whether a human language, a programming language or markup language, that is not a natural language.
3.nounAny language used by people, as opposed to less civilized means of communication, such as the socialization between animals.