baragouin

A pidgin.

She spoke the rude French of the fishing villages, where the language lives chiefly as a baragouin, mingled often with words and forms belonging to many other tongues.

Now in almost every island the negro idiom is different. So often have some of the Antilles changed owners, moreover, that in them the negro has never been able to form a true patois. He had scarcely acquired some idea of the language of his first masters, when other rulers and another tongue were thrust upon him, and this may have occurred four or five times. The result is a baragouin that defies analysis, a totally incoherent agglomeration of speech forms, a bewildering medley, fantastic, astonishing, incomprehensible, almost weird.

A pidgin.

[T]he French he uttered was such a baragouin as would not be comprehended if it were put down on paper; […]

French and Cree have long been native languages to the Metis, and therefore are fully adapted to their traditional cultures. This situation is in marked contrast with the transitory code known as baragouin, a pidgin used by French and Indian groups in the Montreal region in the 17th century[…].

Unintelligible speech; gibberish, jargon.

I am sick of signals and ciphers and secret meetings and such baragouin.

But the denser ambiguity springs from the three baragouins, fantastical languages, that are interspersed among the others. Their effect is to display the arbitrariness of linguistic convention, to show that all language, when looked at from the "outside," is baragouin.