conlang

Noun

constructed language (plural constructed languages)

1. Any language—whether a human language, a programming language, or markup language—that is not a natural language.
   • So if the constructed language is machine code, that is very fine, because the syntax (the grammar) is very simple and the meaning of each instruction can be verified [...]1972, Maurice Marois, Man and Computer: Proceedings, S. Karger, page 120
2. A human language that has been consciously devised by an individual or a group, as opposed to having naturally evolved as part of a culture like a natural language.
   • The first practical constructed language was the south-west German Pastor Schleyer's Volapük from 1879; its complicated grammar and irregular vocabulary made learning difficult, however. The most successful has been Esperanto, devised by the Warsaw ophthalmologist Ludwig Zamenhof in 1887, that...2004, Steven Roger Fischer, A History of Language

   Synonyms:

   artificial language, conlang, conlanguage, planned language

3. (archaic) Any language used by people, as opposed to less civilized means of communication, such as the socialization between animals.
   • It has been said that— when I made the observation, that if they were not married they ought to be—I endeavoured to stab their reputation. Now, I'll prove that I endeavoured to do nothing of the sort. [...] I'll prove it by logic, and I defy all the mathematicians in the habitable globe to known it...1844, Henry Cockton, Sylvester Sound, the somnambulist, pages 203–204