In George Orwell's dystopian novel Nineteen Eighty-Four, the regime's controlled language is called Newspeak.
Newspeak is designed by the Party to replace Oldspeak, the ordinary English language. Its vocabulary is deliberately reduced, with the goal of making independent or rebellious thought increasingly difficult to express.
Newspeak is related to, but distinct from, doublethink. Doublethink is the mental discipline of accepting contradictory ideas, while Newspeak is the engineered language intended to narrow the boundaries of thought. Ingsoc is the Party's name for English Socialism, not the language itself.
Orwell included an appendix about Newspeak that explains its principles and predicted development. The appendix is written as if the Party's system has already become historical, adding another layer to the novel's presentation of political language.